I line team up for murder (9)
I believe the answer is:
eliminate
'murder' is the definition.
(I've seen this before)
'i line team up' is the wordplay.
'up' is an anagram indicator (letters get chucked up).
'i'+'line'+'team'='ilineteam'
'ilineteam' is an anagram of 'ELIMINATE'.
'for' acts as a link.
(Other definitions for eliminate that I've seen before include "Do away with, get rid of" , "Discard - exclude" , "Cut out" , "Annihilate" , "Murder" .)