Excuse a seaman having to find the answer (7)
I believe the answer is:
absolve
'excuse' is the definition.
(thesaurus)
'a seaman having to find the answer' is the wordplay.
'a seaman' becomes 'ab'.
'having' says to put letters next to each other.
'to find the answer' becomes 'solve' (I've seen this before).
'ab'+'solve'='ABSOLVE'
(Other definitions for absolve that I've seen before include "Set free from guilt" , "Grant pardon for" , "Let off the hook" , "Acquit - free of blame" , "Clear of blame or quilt" .)