Unseen cats desperate for nourishment (10)
I believe the answer is:
sustenance
'nourishment' is the definition.
(I know that nourishment can be written as sustenance)
'unseen cats desperate' is the wordplay.
'desperate' is an anagram indicator (a desperate or pathetic spelling).
'unseen'+'cats'='unseencats'
'unseencats' anagrammed gives 'SUSTENANCE'.
'for' acts as a link.
(Other definitions for sustenance that I've seen before include "Nutriment" , "Nourishment" , "Food and drink" , "cooking provides this?" .)