Find topless former spouse in list (5)
I believe the answer is:
index
'list' is the definition.
(I know that index is a more specific form of the action list)
'find topless former spouse' is the wordplay.
'topless' means to remove the first letter.
'former spouse' becomes 'ex' (an ex-spouse).
'find' with its initial letter removed is 'ind'.
'ind'+'ex'='INDEX'
'in' acts as a link.
(Other definitions for index that I've seen before include "Sign of something" , "Register of contents" , "Alphabetical listing in a book" , "Alphabetical list of items" , "One of the fingers" .)