Joining old mate among foremost of noisome crossworders? (5)
I believe the answer is:
nexus
'joining' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'old mate among foremost of noisome crossworders?' is the wordplay.
I cannot really see how this works, but
'old' could be 'ex' (prefix meaning former or onetime) and 'ex' is located in the answer.
The remaining letters 'nus' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for nexus that I've seen before include "Unsex (anag.); a bond" , "joined group" , "Connected series; central point" , "Connection; focal point" , "Bond, connected group" .)