Pull-up and Straighten up

Pull-up noun - An arm exercise performed by pulling yourself up on a horizontal bar until your chin is level with the bar.

Straighten up and pull-up are semantically related. In some cases you can use "Straighten up" instead a verb phrase "Pull-up".

Straighten up verb - Straighten oneself.

Pull-up and straighten up are semantically related. Sometimes you can replace phrase "Pull-up" with "Straighten up", this terms are similar.