1
general::
Phrase(s): in a pinch
as a substitute. • A piece of clothing can be used as a bandage in a pinch. • In a pinch, you can use folded paper to prop up the table leg so the table won’t rock.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
In an emergency, when hardpressed, as in This music isn't what I would have chosen, but it will do in a pinch. This term dates from the late 1400s, when it was put as at a pinch (a usage still current in Britain); pinch alludes to straitened circumstances.
American Heritage Idioms