what does 'tee off' mean? Is it a golf term?

Native speaker’s answer
Rebecca
Yes, it's a golfing term. It means to begin a round or "hole" of golf by hitting the ball which sits on a tee. The "tee" is the small platform that golf balls rest on before players hit them with the golf clubs. Ex: We've been waiting for a cloud to cover the sun so we can tee off for an hour now. Ex: Let's have a drink before we tee off!