Un-

un- + educated → uneducated (“not educated”)

un- + conformity → unconformity (“lack of conformity”)

un- + conference → unconference

un- + dress → undress (“to take one's clothes off”)

un- + lock → unlock (“to undo the locking of”)

Un-cry these tears I cried so many nights Un-break my heart

A prefix is an affix that joins to the beginning of another word. Depending on the prefix, it can slightly or significantly alter the meaning of a word. For example, the English prefix “un-” changes a word into its opposite, as from “do” to “undo,” altering its meaning entirely.

un- + cage → uncage (“to release from a cage”)

un- + tangle → untangle (“to remove the tangling of”)

un- + loosen → unloosen

un- + decipher → undecipher

un- + thaw → unthaw

un- (“1”) + bi- (“2”) + un- (“1”) + -ium (element suffix) → unbiunium (“element 121”)

un- + decillion (“10³³”) → undecillion (“10³⁶”)

un- + vigintillion (“10⁶³”) → unvigintillion (“10⁶⁶”)