Sailor knocked out, as usual (5)
I believe the answer is:
habit
'sailor knocked out as usual' is the definition.
I can't judge whether this definition defines the answer.
'sailor knocked out' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'knocked' becomes 'hit' (I've seen this in other clues).
'out' indicates putting letters inside.
'ab' put inside 'hit' is 'HABIT'.
Can you help me to learn more?
(Other definitions for habit that I've seen before include "Custom, wont" , "It's worn in order" , "Monk's gown or custom" , "can cause addiction" , "Breaking this is hard" .)