Married couple and lieutenant cuddling is stuff of fantasy (4,4)
I believe the answer is:
wish list
'fantasy' is the definition.
Both the definition and answer are singular nouns.
Maybe there's a link between them I don't understand?
'married couple and lieutenant cuddling is stuff' is the wordplay.
'married couple' becomes 'WH' (abbreviations for wife and husband).
'and' means one lot of letters go next to another.
'lieutenant cuddling' becomes 'list' (I am not sure about this - if you are sure you should believe this answer much more).
'stuff' means one lot of letters goes inside another.
'wh'+'list'='whlist'
'whlist' enclosing 'is' is 'WISH LIST'.
'of' is the link.
Can you help me to learn more?
(Other definitions for wish list that I've seen before include "Wants" , "Enumeration of things desired" , "Things one would like to have or do" , "Summary of desirable items or actions" , "collection of wanted items" .)