Indicator of amusement I extracted from comparison (5)
I believe the answer is:
smile
'indicator of amusement' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'i extracted from comparison' is the wordplay.
'extracted from' indicates named letters should be taken away.
'comparison' becomes 'simile' (simile is a kind of comparison).
'simile' with 'i' taken out is 'SMILE'.
Can you help me to learn more?
(Other definitions for smile that I've seen before include "Facial expression showing pleasure" , "Indicate pleasure with lips movement" , "Show you're pleased" , "Visually express amusement" , "Happy facial expression" .)