Verb

(en verb)

To cause to become straight.

To become straight.

To put in ; to tidy up.

to straighten one's affairs, or an account

* {{quote-news

, year=2011 , date=Septembe 24 , author=Ben Dirs , title=Rugby World Cup 2011: England 67-3 Romania , work=BBC Sport citation , page= , passage=Tuilagi and Ashton started in lively fashion, centre Tuilagi doing what he does best, straightening and bursting into the line, and Ashton always looking to leave his wing and get involved in the action.}}

To clarify a situation or concept to (an audience).

(slang) To .

To stand up, especially from a sitting position.

Verb

(en verb)

To make something flat or flatter.

As there was a lot of damage, we chose the heavy roller to flatten the pitch.

Mary would flatten the dough before rolling it into pretzels.

(reflexive) To press one's body tightly against a surface, such as a wall or floor, especially in order to avoid being seen or harmed.

* 1994 , , ch. 2:

With a bolt of fright he remembered that there was no bathroom in the Hob-house Room. He leapt along the corridor in a panic, stopping by the long-case clock at the end where he flattened himself against the wall.

To knock down or lay low.

The prize fighter quickly flattened his challenger.

To become flat or flatter; to plateau.

Prices have flattened out .

To be knocked down or laid low.

(music) To lower by a semitone.

To make vapid or insipid; to render stale.

(computer graphics) To combine (separate layers) into a single image.