Wandering sailor and worker concealing blunder (8)
I believe the answer is:
aberrant
'wandering' is the definition.
(I've seen this before)
'sailor and worker concealing blunder' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'and' means one lot of letters go next to another.
'worker' becomes 'ant' (worker is a type of ant).
'concealing' indicates putting letters inside.
'blunder' becomes 'err' (to err is to make a mistake or blunder).
'ab'+'ant'='abant'
'abant' placed around 'err' is 'ABERRANT'.
(Other definitions for aberrant that I've seen before include "Unusual" , "Divergent from the normal" , "Going wrong" , "'Deviant, behaviour say (8)'" , "Deviating from what is accepted" .)