1. To begin a game of golf by hitting the ball on the first hole. We tee off at 9 AM, so you should arrive at the golf course around 8:30. It was already nearing 90 degrees when we teed off, so we weren't sure if we would make it through all 18 holes.

2. By extension, to begin or mark the beginning of something; to kick something off. In this usage, a noun or pronoun can be used between "tee" and "off." They teed off the party with a game of musical chairs. Let's tee things off with some brainstorming exercises.

3. To make someone particularly annoyed, angry, or frustrated. In this usage, a noun or pronoun can be used between "tee" and "off." It really tees me off the way people drive in the bus lane, when they clearly aren't supposed to! Nothing teed my mom off more than having guests come into the house with dirty shoes.