The crossword solution for the term 'ANTI' is a four-letter word. ANTI is a prefix that means 'AGAINST' or 'opposing'. It can be used to describe someone who is AGAINST a particular idea, such as an ANTI-hero, an ANTI-lock, or an ANTI-monarchist. An ANTI-hero is a protagonist who lacks traditional heroic qualities, such as courage and nobility. An ANTI-lock is someone who opposes the use of locks, such as on doors or safes. An ANTI-monarchist is someone who is opposed to the rule of a monarch or monarchy.