1. To move along in the air or on a surface (typically water) while being propelled only by wind or the current of the water, and without a definition direction. We just drifted along on an inflatable raft until we reached the other end of the river. That feather seemed like it drifted along as if by magic.

2. By extension, to live one's life without much effort or direction. I'm worried because you're just drifting along through high school with no interest in planning your future!