tie up

Verb

tie up (third-person singular simple present ties up, present participle tying up, simple past and past participle tied up)

1. To secure with rope, string, etc.
   • Don't forget to tie up your hair before you bake.
   • The robbers tied up the bank employees before forcing a way into the vault.
2. (idiomatic) To occupy, detain, keep busy, or delay.
   • He has been tying up the phone lines for hours now.
   • Just how much traffic was tied up was not immediately determined but in Houston about 150 cars of grain arrived yesterday and could not be transferred to the port because of the Port Terminal Railroad picketing.1964 June 16, “Surprise Strike Stops Traffic On 6 Railroads”, in The Indianapolis Star, volume 62, number 11, Indianapolis, Ind., page 3
3. (idiomatic) To complete, finish, or resolve.
   • I'd like to tie up the project before I leave.
   • Scottish Fishermen’s Federation chief Elspeth Macdonald said the whitefish fleet could have had to tie up for the entire year because of the recommendation.2025 December 5, “Isles economy could take £16m hit from cod quota slash, fishing official says”, in Shetland News
4. To immobilize a capital: make a capital investment that makes that capital unavailable.
   • Don't tie up your capital in aging accounts.