How unkind to ring us about nothing (7)
I believe the answer is:
callous
'how unkind' is the definition.
'callous' can be an answer for 'unkind' (thesaurus). I am not certain of the 'how' bit.
'ring us about nothing' is the wordplay.
'ring' becomes 'call' (synonyms).
'about' says to put letters next to each other.
'nothing' becomes 'O' (looks like zero - 0).
'us' put after 'o' is 'ous'.
'call'+'ous'='CALLOUS'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for callous that I've seen before include "Insensitive, cruel" , "Hard and unfeeling" , "Emotionally hardened" , "Cruel and unfeeling" , "Heartless" .)