'tie up' definitions:

Definition of 'tie up'

(from WordNet)
verb
Secure with or as if with ropes; "tie down the prisoners"; "tie up the old newspapers and bring them to the recycling shed" [syn: tie down, tie up, bind, truss]
verb
Invest so as to make unavailable for other purposes; "All my money is tied up in long-term investments"
verb
Restrain from moving or operating normally; "Traffic is tied up for miles around the bridge where the accident occurred"
verb
Secure in or as if in a berth or dock; "tie up the boat" [syn: moor, berth, tie up]
verb
Finish the last row [syn: tie up, bind off]

Synonyms of 'tie up'

From: Moby Thesaurus