Force Morgan out: he's wet at work (7)
I believe the answer is:
frogman
'he's wet at work' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'force morgan out' is the wordplay.
'force' becomes 'F' (symbol used in Physics e.g. f=ma).
'out' indicates an anagram (out can mean wrong or inaccurate).
'morgan' is an anagram of 'rogman'.
'f'+'rogman'='FROGMAN'
Can you help me to learn more?
(Other definitions for frogman that I've seen before include "Swimmer employed in underwater operations" , "Male diver" , "Diver with breathing equipment" , "Rubber-suited diver" , "Swimmer working underwater" .)