Entertained underwater explorer, male (8)
I believe the answer is:
diverted
'entertained' is the definition.
(diverting is a kind of entertaining)
'underwater explorer male' is the wordplay.
'underwater explorer' becomes 'diver' (someone diving under the sea).
'male' becomes 'Ted' (man's name).
'diver'+'ted'='DIVERTED'
(Other definitions for diverted that I've seen before include "Changed direction, deviated" , "Taken out of oneself" , "Change course and entertained" , "was amusing" , "Distracted, entertained" .)