A quiet morning? It's just not true! (4)
I believe the answer is:
sham
'just not true' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'a quiet morning?' is the wordplay.
'a quiet' becomes 'sh' ('sh' is used to tell someone to be quiet).
'morning?' becomes 'am' (as in 12:00 AM).
'sh'+'am'='SHAM'
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for sham that I've seen before include "Phoney, bogus" , "Mash, being false" , "Unreal" , "imitation" , "Pretence; bogus, false" .)