Friendly with a soft associate (5)
I believe the answer is:
pally
'friendly' is the definition.
(similar in meaning)
'with a soft associate' is the wordplay.
'with' says to put letters next to each other.
'a soft' becomes 'p' (musical abbreviation for 'piano').
'associate' becomes 'ally' (ally is a kind of associate).
'p' next to 'ally' is 'PALLY'.
(Other definitions for pally that I've seen before include "Very familiar" , "Thick" , "Close, friendly" , "Intimate" , "China may be so" .)