lose track of something/someone

lose track of (someone or something)

1. To not pay attention to (and thus forget about or misplace) something. I'm sorry I'm late—we were having so much fun that I completely lost track of time. Do you know what time the party starts? I've lost track of my invitation.
2. To no longer communicate with someone regularly. Unfortunately, I lost track of my college roommate, so I have no idea how she's doing now.
See also: lose, of, track

lose track of something/someone

COMMON If you lose track of something or someone, you no longer know what is happening to them or where they are. His family lost track of him under his new name. You may have wondered how the fund's administrators could lose track of £20 million. We were chatting and we just lost track of the time.
See also: lose, of, someone, something, track