In the cinema, maybe, he's concerned with hard water (6)
I believe the answer is:
iceman
'in the cinema maybe he's concerned with hard water' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'he's concerned with hard water' is the wordplay.
I cannot quite understand how this works, but
'water' could be 'ice' (ice water is a kind of water) and 'ice' is located in the answer.
'he' could be 'man' (I've seen this in another clue) and 'man' is found within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for iceman that I've seen before include "Cold character in cinema" , "Professional killer - jewel thief - Eugene O'Neill character" , "assassin" , "Eugene O'Neill's figure of 'death' (the one who cometh!)" , "He delivers" .)