Worn by a sailor in a blow? (5)
I believe the answer is:
habit
'worn' is the definition.
(I've seen this before)
'a sailor in a blow?' is the wordplay.
'a sailor' becomes 'ab' (abbreviation for able seaman).
'in' indicates putting letters inside.
'a blow?' becomes 'hit' (I am not sure about this - if you are sure you should believe this answer much more).
'ab' placed inside 'hit' is 'HABIT'.
'by' is the link.
Can you help me to learn more?
(Other definitions for habit that I've seen before include "Monk's garb" , "Custom; clothing" , "Acquired pattern of behaviour" , "Dress - custom - practice" , "Breaking this is hard" .)