(idiom) a major crisis or betrayal occurring very close at hand, such as among close friends or family; literally "a calamity arising from one's armpit"

trouble or danger coming from those closest to oneself or from within one's inner circle

trouble or accidents occurring very close by, such as in one's own immediate circle or household; literal meaning is trouble arising from under one's own armpit

misfortune or disaster arising from one's immediate circle or very close surroundings