Sailor I would expect, initially, to tolerate (5)
I believe the answer is:
abide
'to tolerate' is the definition.
(synonyms)
'sailor i would expect initially' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'i would' becomes 'I'd'.
'initially' says to take the initial letters.
The initial letter of 'expect' is 'e'.
'ab'+'id'+'e'='ABIDE'
(Other definitions for abide that I've seen before include "Put up with" , "Endure, tolerate" , "Stomach" , "Wait for" , "Tolerate - dwell" .)