Asking what a word means in front of people is braver than pretending and missing the point.

Pretending buys you about four seconds of looking fine and costs you the rest of the conversation. Once one word slips past you, everything built on top of it slips too, and by the end you are nodding at a point you cannot follow. Asking looks like the bigger risk because it happens out loud, in front of people. Quietly losing the whole thread is worse.

Next time a word goes by that you do not know, just say so. Four plain words work fine: what does that mean. Usually someone nearby was hoping you would ask first.