sometimes followed by up or out:
to make or become straight - (transitive)
to make neat or tidy
WordReference Random House Learner's Dictionary of American English © 2025
straight•en /ˈstreɪtən/USA pronunciation
v.
WordReference Random House Unabridged Dictionary of American English © 2025- to (cause to) become straight, orderly, neat, or tidy: [no object]His curly hair straightens if he doesn't wash it every day.[~ (+ out) + object]Straighten your tie; it's crooked.[no object* (~ + up)]Let's straighten (up) a bit before Grandpa comes over.[~ (+ up) + object]Let's straighten (up) your room a bit.[~ + object (+ up)]Let's straighten your room (up) a bit.
- straighten out:
- to (cause to) become free of confusion or difficulties: [~ + object + out]Let's see if we can straighten this problem out.[~ + out + object]The police tried to straighten out the mess.
- to improve in conduct or character: [no object]After he got married he straightened out nicely.[~ + object + out]A few years in the marines will straighten him out.
straight•en
(strāt′n),USA pronunciation v.t., v.i.
straight′en•er, n.
- to make or become straight in direction, form, position, character, conduct, condition, etc. (often fol. by up or out).
- straight + -en1 1535–45
Collins Concise English Dictionary © HarperCollins Publishers::
sometimes followed by up or out:
'straighten' also found in these entries (note: many are not synonyms or translations):