1. To move, pass, or lapse quickly. Wow, the time has really sped by—I can't believe we're nearly at the end of our trip! I tried to catch the license plate number of the car speeding by, but it was too fast.

2. To move past someone or something very quickly. Followed by a noun or pronoun of the person or thing being passed. It really startled me when the motorcycle sped by our car. I tried to get the teacher's attention, but she sped right by me.