slightly sour or acidic, not strongly so, often describing a mild tanginess

kyselkavý, kyselý
too confident or proud in expressing oneself, in a way that is annoying to others

neurvalý, domýšlivý
(of some plants or animals) having sharp, needle-like things on the surface of their body

trnitý, ostnatý
hard-working and productive

pracovitý, usilovný
extremely evil or wicked, typically involving illegal or immoral actions

zlovolný, nečestný
keeping the title of their former position after retirement as an honor, especially of a university professor

emeritní, čestný (v kontextu akademickém)
(of animals and plants) found and developed only in a particular place and not been brought from elsewhere

domorodý, původní
characterized by excessive ingratiation or flattery, often in a way that seems insincere or manipulative

olejovitý, ljubivý
done or happening naturally, without any prior thought or planning

spontánní, přirozený
