(archaic) Alternative form of en perdre son latin

to do as best one can, to do one's best, to do one's utmost, to give it one's best shot

(sports) own goal

Alternative spelling of être sur son trente et un

of one's own accord, off one's own bat, on one's own initiative, at one's own instigation

(informal) sure of what one is doing, confident of success, certain of succeeding

in self-defense / reluctantly, unwillingly, against one's will

(Belgium, transitive, informal) to guess, to predict; to invent, to pull out of one's ass; to know

to be conspicuous by one's absence

(transitive, figuratively) to take under one's wing