Get into shape for being married (4)
I believe the answer is:
form
'get' is the definition.
(thesaurus)
'for being married' is the wordplay.
'being married' becomes 'm' (abbreviation, e.g. in genealogy).
'for'+'m'='FORM'
'into shape' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for form that I've seen before include "Acceptable conduct" , "Group of schoolchildren < > construct" , "Make" , "Class; schedule" , "A hare's hide-out" .)