Not, absence of a quality

Unstoppable, Unmodified, Unconvinced, Unnamed, Unnoticeable, Unpaired

Contrary to, opposite of

Untidiness, Unbelief, Unrest, Unaptness, Untruth

The reverse of an action

Untie, Uncover, Untangle, Unlock

Situated in a higher position

Upstairs, Upland, Upstate, Upriver, Upstage, Upstream, Upstroke

Upward movement, direction

Updraft, Upsurge, Upside, Upward

Lift, raise toward a higher level, position

Upcast, Uplift, Uprise, Upthrow, Upthrust, Uproot, Upraise

Increase in size, scale, etc.

Upscale, Up-tempo, Upbeat, Uproar

To a more recent time

Update

To a better state

Upgrade, Uplift, Upturn

Situated in a lower position

Downriver, Downland, Downfield, Downhill

Downward movement, motion

Downcast

Reduce to a lower level, position, size, scale

Downgrade, Downfall, Downscale, Downsize, Downturn, Downbeat, Downshift

Beneath, directly under something else

Underground, Underlay, Underline, Underworld, Underclothes, Undergarment, Underwear

Below, lower part, side, position

Underlip, Underarm, Undershrub, Underside

Less than usual, not enough

Undergrowth, Underman, Undernourished, Underpayment, Underprice, Underemployed, Undercharge,

Subordinating, lower rank, position

Undersecretary, Undermanager, Undergraduate

Half

Midway, Midcap, Midlife, Midline, Midnight, Midpoint

Too much/excessive

Overreact, Overanxious, Overboil, Overdress, Overcharge, Overdue, Oversimplify

Upper, outer

Overcoat, Overleaf, Overclothe, Overshoe, Overskirt

Denoting a location above

Overhead, Overcast, Overhang, Overfly

To a downward direction

Overthrow, Overlook, Overshadow, Oversee

Across, beyond a place

Transcultural, Transcontinental, Translunar, Transnational, Transoceanic, Transpolar, Transatlantic

Through

Transdermal, Transfuse

Denoting change into another state

Transform, Transfigure, Transubstantiate, Transgender, Transsexual

To move to another place

Translocate, Transplant, Transship

Too much, beyond

Transfinite, Transfix, Transmundane

Going before, preceding

Forerunner, Forefather, Forebear, Forenoon, Forego, Foreplay

The front part of something

Forehead, Forearm, Forecastle, Foredeck

In front

Foreshorten, Forecourt, Foreground

In advance

Forebode, Forecast, Forefend, Foreknow

Small, short

Miniskirt, Minibar, Minicab, Mini-market, Mini-golf

Make, cause

Bewitch, Befriend, Bedazzle, Become

A former state

Ex-wife, Ex-boyfriend, Ex-husband, Ex-member, Ex-Muslim

Together

Confederate, Conjoin

Removal, reversal

Dehydrate, Defrost, Deforest, Decaffeinate

The meaning of the word is changed to the opposite

Defame, Deconstruct, Demerit, Decamp, Decode, Deform

Denoting removal

Disburden, Disarm, Discover, Disbud, Disambiguate

Denoting reversal

Disembark, Discharge, Distrust, Disjoin, Disconnect, Disintegrate, Dismantle

Denoting absence, opposite to

Dissimilar, Dislike, Disappear, Dishonest, Dissatisfied

Not

Inactive, Incapable, Inexact, Inexpensive, Ingenious, Insane

Without, lacking

Indecision, Indiscretion, Inexperience, Ineffectiveness

Having a causative function

Inflame, Intoxicate, Inaugurate, Inanimate, Inbreathe, Inbreed

In, into, towards, within

Inbox, Inflow, Inhale, Inland, Innate, Intake

Not

Illegal, Illiteracy, Illogical, Illiberal, Illegitimate, Illiberalize, Illegalize, Illegitimate

Not

Impossible, Imperfect, Impassive, Impracticability

Having a causative function

Imperil, Imbricate

In, into

Immigrate

Not

Irresponsible, Irrational, Irreclaimable, Irregular, Irreligious, Irreversible

Not

Nonverbal, Nonexistent, Non-nuclear, Nonalcoholic, Nonflavored, Nonglutinous, Noninfectious Nonarbitrary, Nonuniformly, Non\fiction

Without

Nonevent, Nonstop

Denoting absence

Non-attendance, Non-interference, Noncooperation, Nonunion

Not causing or requiring

Nonskid, Nonstick, Nonslip

Lower position or level

Subalpine, Subway, Submerge, Submarine, Subocean

Forming a subordinate part of a whole

Subculture, Subclass, Subdivision, Subsection, Subclause, Subcommittee, Subcontract

Secondary in rank, subordinate

Subdeacon, Subeditor

Of lesser quality, inferior, somewhat, nearly

Subhuman, Substandard, Subaquatic, Subantarctic subacid, Subcontinent, Subtropical

Denoting a later or secondary action of the same kind

Subdivide, Subcontract, Sublease, Sublet, Subsequent

Between, among

Interlink, Intersection, Intercellular, Interconnect, Interdepartment

Mutually, reciprocally

Interdependent, Interactive, Interchangeable, Interrelationship

Back to a previous state

Return, Reinstate, Relapse, Recall, Rebound, Refund, Reimbursement

Mutually

React

In opposition

Repel

With negative force

Recant

With intensive repetitive force

Refine, Refoulement, Repress

Below

Infrared, Infrastructure, Infraorder, Infrahuman

Within, inside

Intracellular, Intracerebral, Intradepartmental, Intralinguistic, Intramural, Intrastate

Before

Preassembled, Precut, Prefix, Preorder, Preregistration

Supporting

Pro-choice, Prolabor

Substituting for

Procathedral, Proconsul

A motion forward, out, or away

Proceed, Proclivity

After in time/order

Postgraduate, Postdate, Postmodern, Postbiblical, Postdoctoral, Postmodernism

Once more, anew

Redo, Reestablishment, Refurbish, Recount, Regelation, Reassure

Half

Semicircle, Semicircular, Semitone

Occurring twice in a period of time

Semiannual, Semiweekly, Semimonthly

Partly, almost

Semiliquid, Semi-conscious, Semi-darkness, Semi-skilled, Semifinal

Beyond a limit, on the other side of

Ultraviolet, Ultralight, Ultrasonic, Ultramicroscopic

Extreme degree, very

Ultra-ambitious, Ultra-modern

Outside, beyond

Extraterrestrial, Extracellular, Extra-constitutional, Extra-parliamentary

Beyond the scope of

Extracurricular, Extraordinary, Extraordinaire, Extrasensory

Two, having two

Bicultural, Bipolar, Bisexual, Bicolored

On both sides, directions

Bilateral, Biconcave

Occurring twice

Biweekly, Bicentennial

Three, having three

Tricycle, Triangle, Trihydroxy, Trivalent

Occurring every three

Trimonthly, Triannually

Many

Multimedia, Multicolored, Multistory, Multimillion

Many

Polyglot, Polytechnic

Extra-large of its kind

Supermarket, Supercontinent, Supergiant, Superhighway

Beyond, over

Supernormal, Superabundant, Supercharge, Supercritical, Superpower

Outstanding

Superstar, Supermodel, Supermodel, Superhero, Superman, Superwoman, Superhuman

Higher in rank, superior to

Superintendent, Supervisor

Placed on, positioned on something

Superimpose, Superinfection, Superpose, Superstructure

Opposition, against

Counterattack, Counter-offensive, Counterpoint, Countercharge, Counteract, Counter-terrorist

Complementary

Counterfoil

Corresponding

Countertrade, Counterpart

Duplicate or substitute

Counterfeit

Together, common

Cooperation, Coproduction, Coworker, Copartner, Coeducation

After, later, subsequent to

Postdoctoral, Postmodern, Postcolonial, Postwar

Before, backwards

Retroactive, Retrorocket, Retroscape

Distant, transmission over distances

Television, Telework, Telegram, Teleguide, Telemonitor

Against, opposed to

Antifeminism, Anticlerical, Anticlockwise, Antiracist, Anti-government

Inhibiting, counteracting

Antifreeze, Antibacterial, Antihistamine, Anti-aircraft

Bad, difficult (medical)

Dysfunction, Dysrhythmic, Dystrophic, Dyslogistic

Small-scale

Micrometer, Microcar, Microscope, Microphone, Microorganism

Half

Hemisphere, Hemicycle, Hemimorphic, Hemilingual

Original, primitive

Prototype, Protostar

First, earliest

Protomartyr

One, alone, single

Monolingual, Monocarboxylic

Beyond

Metaphysic, Metafiction, Metathesis, Metasomatism

Denoting change

Metamorphosis

Situated behind or after

Metaphase, Metapneumonic

Above normal

Hyperactive, Hyper-critical, Hypercorrection, Hyperextended, Hypersonic

One's own, by oneself

Autobiography, Autograph

By itself, self-sufficient

Automobile, Autotoxidation, Auto-analysis, Autofocusing

Wrong, badly

Misplace, Misrepresentation, Misdo, Mistrial, Misprint, Misadventure

Not, denoting lack

Misfire, Mistrust,

Wrong, faulty

Malfunction, Malformed

Improper manner

Maltreat, Malpractice

Inadequate

Malnourishment, Malnutrition

Not, denoting lack

Maladroit

Make, cause to be

Enable, Endanger, Enthrall, Ensure, Enarm

Put into, on

Engulf, Entomb, Enthrone

Conversion into the specified state

Encrust, Ennoble, Enliven

To go into, on

Enplane

To cover with, surround

Enmesh, Enrobe

As an intensifier

Encourage, Entangle, Endure

Over, beyond

Surrealism, Surcharge

Upon, over

Surface, Surcoat, Surname