1. To move past (someone or something) while having smooth, continual contact with the ground. She fell on the ice while she was skating and slid by a bunch of popular kids from school. We were having coffee by the window of the restaurant when suddenly a huge truck went sliding by.

2. Of time, to pass very quickly and unnoticeably. These summer days just slide by, don't they? I can't believe it's nearly August already! The years keep sliding by faster and faster.

3. To progress through something, such as school, a project, one's job, etc., with a minimal amount of effort or attention. I've been really bored with my job, and I feel like I've just been sliding by lately. If you think you can slide by the whole semester and still pass this course, you are sadly mistaken!