A jacket-like garment with very long sleeves which can be secured in place, thus preventing the wearer from moving his or her arms. Often used in psychiatrichospitals to prevent patients from injuring themselves or others.
A metaphor used to describe a range of situations seen as (unpleasantly?) confining or restricting.
2009, Michael Giffin, Quadrant, November 2009, No. 461 (Volume LIII, Number 11), Quadrant Magazine Limited, page 99:If we remain in one discipline, we remain in a straitjacket; an adequate theory of language evolution requires a lot of interdisciplinary work.