noun
gall
GAWL/ɡɔːl/
Rude or shameless boldness.
The patron has the gall to take fries from another diner's plate.

Etymology
Old English galla meant bile. Humoral medicine helped give the word an emotional sense, “rancor” or “embittered spirit,” before its later informal use for shameless boldness.
In context
if you're at a dinner party and a stranger has the gall to ask you an impudent question