Getting hard? It's what I'm doing (7)
I believe the answer is:
setting
'doing' is the definition.
('set' can be a synonym of 'do')
'getting hard? it's what i'm' is the wordplay.
I cannot quite understand how this works, but
'hard?' could be 'set' (similar in meaning) and 'set' is found within the answer.
'i'm' could be 'i' (I've seen this in other clues) and 'i' is located in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for setting that I've seen before include "Scene" , "Compiler's job" , "situation" , "approaching the horizon" , "Surroundings; hardening" .)