Around noon, son seen cooking tripe (8)
I believe the answer is:
nonsense
'tripe' is the definition.
(I've seen this before)
'around noon son seen cooking' is the wordplay.
'around' is an insertion indicator.
'noon' becomes 'n' (abbreviation).
'cooking' indicates an anagram (letters cooked up into a new form).
'son'+'seen'='sonseen'
'sonseen' anagrammed gives 'nosense'.
'n' put into 'nosense' is 'NONSENSE'.
(Other definitions for nonsense that I've seen before include "tripe" , "Language without meaning" , "Quick look" , "Words or ideas that don't make sense" , "Rubbish, rot" .)