Day First Lady cut advance (7)
I believe the answer is:
develop
'advance' is the definition.
(thesaurus)
'day first lady cut' is the wordplay.
'day' becomes 'd'.
'first lady' becomes 'eve' (I've seen this before).
'cut' becomes 'lop' (lopping is a kind of cutting**).
'd'+'eve'+'lop'='DEVELOP'
(Other definitions for develop that I've seen before include "Grow, advance" , "Grow, progress" , "Grow, elaborate" , "Result" , "issue" .)