Lebanese man almost upset sailors (4,6)
I believe the answer is:
able seamen
'sailors' is the definition.
(able seaman is a kind of sailor)
'lebanese man almost upset' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'upset' indicates anagramming the letters.
'lebanese'+'man'='lebaneseman'
'lebaneseman' with its last letter removed is 'lebanesema'.
'lebanesema' is an anagram of 'ABLE SEAMEN'.
(Other definitions for able seamen that I've seen before include "ratings" , "sailors" .)