un-

un-prefix

Un- turns a word into its opposite: not, or doing the opposite of an action so that something goes back to how it was.

1. notadded to an adjective or an adverb, or to a form such as known or expected, to make a word meaning not that

   Un- goes with everyday adjectives (unhappy, unkind, unable) and with participles used as adjectives: a regular one ending in -ed (unfinished), an irregular one (unknown, unbroken), or one ending in -ing (unwilling, unconvincing). Many words from Latin take in-, im-, il-, or ir- instead (impossible, illegal, irregular), and some take dis- or non- (dishonest, nonstop); no rule says which, so learn each word. Not un- is a mild positive: not unhappy means fairly happy.

   • The test was unfair.
   • She gave an unexpected answer.
   • It is unlikely to rain today.
   • He has been unemployed for months.

   Compare in (in-, im-, il-, and ir- do the same job for many words from Latin: impossible, illegal); dis (dis- makes the opposite of some adjectives and verbs: dishonest, disagree); non (non- means simply not, without any judgment: nonsmoker)

2. undoadded to a verb to make a verb meaning do the opposite of the action, so that something goes back to how it was

   Verbs with un- often mean open, loosen, or take off: unlock, untie, unbutton, undress, unwrap. New verbs of this kind are made freely, especially in computing: unsubscribe, unfollow, unsend.

   • Untie the rope before you leave.
   • I cannot unlock the door with this key.
   • We unpacked the boxes as soon as we arrived.
   • She unfriended him after the argument. (computing; a newer word)

3. removeadded to a noun to make a verb meaning take away the thing named, or take someone or something out of it

   • The reporter unmasked the man behind the plan.
   • The storm unearthed old bones in the garden.
   • The vote unseated the mayor.