a distinct layer or level within a system, often conceived as having depth or hierarchy
a problem or question that is confusing and needs a lot of skill or effort to solve or answer
a section of additional material that is usually added at the end of a book
a single-celled microorganism that typically reproduces by cell division and can be found in various environments, including soil, water, and living organisms
a large retail store selling various goods, or a particular type of goods
a shell beads used by some Native American tribes as currency or ceremonial items
a device with a long thin bar and a weight at the end that swings side to side to keep a clock working
the wall separating the audience and the stage in a theater hall, including the arch on its top
a tarred fiber used for caulking seams in wooden ships and as insulation in plumbing
a single piece of information or a reference point used in analysis or measurement
a concise collection or summary of information, typically presented in a single volume or document
severe criticism or public condemnation, often directed at someone's actions or behavior that is considered shameful or disgraceful
a point or support on which a lever pivots or rotates in order to lift or move objects
(anatomy) the bone structure that surrounds and protects the brain
an unpleasant or noxious odor, typically emanating from decaying matter or industrial processes
a period of one thousand years, usually calculated from the year of the birth of Jesus Christ
a temporary suspension or halt of an ongoing activity, often imposed by an authority
a formal expression of praise or tribute, typically delivered in speech or writing
a facility offering care for patients with mental or medical conditions needing extended treatment
a questionable or unproven remedy or treatment, often sold with exaggerated claims of effectiveness