Ties up venue (4)
I believe the answer is:
site
'venue' is the definition.
(I've seen this in another clue)
'ties up' is the wordplay.
'up' indicates an anagram (letters get chucked up).
'ties' is an anagram of 'SITE'.
(Other definitions for site that I've seen before include "Location or piece of land" , "internet location" , "Position; situation" , "Web location; place" , "Location (of building, dig etc)" .)