Senior again tore about clutching mug (2,1,7,3)
I believe the answer is:
of a certain age
'senior' is the definition.
Both the definition and answer are singular nouns.
Perhaps there's a link between them I don't understand?
'again tore about clutching mug' is the wordplay.
I cannot really see how this works, but
an anagram of 'again' is 'ainag' which is located in the answer.
'about' could be 'of' and 'of' is found within the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for of a certain age that I've seen is " When one is no longer young".)