All women do is watch it crossing new area (3,5)
I believe the answer is:
hen party
'all women do' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'watch it crossing new area' is the wordplay.
'watch it' becomes 'hey' (I can't justify this - if you can you should believe this answer much more).
'crossing' means one lot of letters goes inside another (to cross can mean to go over or around).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'area' becomes 'part' (eg an area or part of a city).
'n'+'part'='npart'
'hey' placed around 'npart' is 'HEN-PARTY'.
'is' is the link.
Can you help me to learn more?
(Other definitions for hen party that I've seen before include "Event to which stags are not invited" , "pre-wedding bash" , "Pre-wedding get-together for the bride" , "Women's gathering (colloq.)" , "do for prospective union member" .)