Write music, say, and outlast men oddly ignored (6)
I believe the answer is:
notate
'write music' is the definition.
(I've seen this in another clue)
'and outlast men oddly ignored' is the wordplay.
'and' becomes 'n' (common abbreviation for 'and').
'oddly ignored' means one should take alternating letters (letters in odd-numbered positions are removed).
'outlast'+'men'='outlastmen'
The alternate letters of 'outlastmen' are 'otate'.
'n'+'otate'='NOTATE'
'say' is the link.
(Other definitions for notate that I've seen before include "At Eton (anag.)" , "Put down in writing" , "Write in system of signs or symbols" , "Compose" , "Add runs to score, possibly" .)