Bag lady regularly eats one (4)
I believe the answer is:
land
'bag' is the definition.
(thesaurus)
'lady regularly eats one' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'eats' means one lot of letters goes inside another.
'one' becomes 'an' (I've seen this in other clues**).
The alternate letters of 'lady' are 'ld'.
'ld' placed around 'an' is 'LAND'.
(Other definitions for land that I've seen before include "win" , "Come down; territory" , "Secure" , "people" , "See 5" .)