Yes, ask if the term is material to understanding the case.

A short clarification is better than building several minutes of analysis on a misunderstood concept. You can say: "Just to make sure I'm interpreting that correctly, does X mean...?"

Do not ask for definitions of ordinary business concepts you are expected to know, but industry-specific terminology is different. Interviewers want to see that you can identify what you need to solve the problem.

Once clarified, move on without apologizing. The goal is efficient problem solving, not proving that you know every term from every sector.