lose track of something/someone

lose track of (someone or something)

1. To lose visibility of, forget about, misplace, or neglect to pay close attention to 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. I was watching the bird through my binoculars until I lost track of it in the canopy.
2. To unintentionally decrease frequency of communication with someone over time until no further contact takes place. Unfortunately, I lost track of my college roommate, so I have no idea how she's doing now.
See also: lose, of, track
Farlex Dictionary of Idioms.

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
Collins COBUILD Idioms Dictionary, 3rd ed.
See also:
  • a run on (something)
  • a rush on (something)
  • address (one's) comments to (someone or something)
  • address comments or remarks to
  • address (one's) remarks to (someone or something)
  • be in it for
  • be pressed for time
  • be pushed for time
  • be at a disadvantage
  • at a disadvantage