Wash and clean regularly beneath (7)
I believe the answer is:
launder
'wash' is the definition.
('launder' can be a synonym of 'wash')
'clean regularly beneath' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'beneath' becomes 'under' (I've seen this before).
The alternating letters of 'clean' are 'la'.
'la'+'under'='LAUNDER'
'and' is the link.
(Other definitions for launder that I've seen before include "Perhaps decriminalise" , "Clean, clothes or mafia money" , "Cleanse (material or money)" , "Make clean again - clothes or money" , "Wash or cleanse, clothes or money" .)