Spill measure close to bar (5)
I believe the answer is:
taper
'spill' is the definition.
(thesaurus)
'measure close to bar' is the wordplay.
'measure' becomes 'tape' (I've seen this before**).
'close to' suggests the final letters (the close/ending of).
The last letter of 'bar' is 'r'.
'tape'+'r'='TAPER'
(Other definitions for taper that I've seen before include "Get to the point" , "Prate (anag.)" , "Get narrower towards end" , "recording artist" , "Thin candle, spill" .)