Small cat almost longing to stand (7)
I believe the answer is:
stomach
'stand' is the definition.
(synonyms)
'small cat almost longing' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'cat' becomes 'tom' (a tom is a male cat).
'almost' means to remove the last letter (most of the word but not all of it).
'longing' becomes 'ache' (I've seen this before).
'ache' with its last letter taken away is 'ach'.
's'+'tom'+'ach'='STOMACH'
'to' acts as a link.
(Other definitions for stomach that I've seen before include "Endure; organ" , "Endure, accept" , "Tolerate; appetite" , "Digestive organ" , "Breadbasket (informal)" .)