Verb
1. straighten up or out; make straight
2. make straight
3. get up from a sitting or slouching position;
"The students straightened when the teacher entered"4. put (things or places) in order;
"Tidy up your room!"5. straighten by unrolling;
"roll out the big map"6. make straight or straighter;
"Straighten this post""straighten hair"