Bend rounded by a cordial general (7)
I believe the answer is:
cassius
'a cordial general' is the definition.
The definition suggests a singular noun which matches the answer.
'bend rounded' is the wordplay.
I cannot quite see how this works, but
'bend' could be 'u' (a U-bend is a kind of bend - pipe under sink) and 'u' is located in the answer.
The remaining letters 'cassis' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'by' is the link.
Can you help me to learn more?
(Other definitions for cassius that I've seen before include "Conspirator against 8" , "Birth name of Muhammad Ali, -- Clay" , "He had 'a lean and hungry look' according to Shakespeare" , "Roman character" , "Conspirator in the murder of Julius Caesar" .)