Definition of "straighten"

straighten

/ˈstɹeɪtn̩/

verb
third-person singular simple present straightens, present participle straightening, simple past and past participle straightened
1. (transitive) To cause to become straight.
2. (intransitive) To become straight.
3. (transitive) To put in order; to sort; to tidy up.
  Quotations
  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.
  2011 September 24, Ben Dirs, “Rugby World Cup 2011: England 67-3 Romania”, in BBC Sport‎
4. (transitive) To clarify a situation or concept to (an audience).
5. (transitive, slang) To bribe or corrupt.
6. (intransitive) To stand up, especially from a sitting position.