Trim sailor reaching bank (7)
I believe the answer is:
abridge
'trim' is the definition.
(I've seen this before)
'sailor reaching bank' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'reaching' says to put letters next to each other.
'bank' becomes 'ridge'.
'ab'+'ridge'='ABRIDGE'
(Other definitions for abridge that I've seen before include "Crop" , "Make a precis of" , "Shorten by using fewer words" , "Edit down" , "Abbreviate, contract" .)