As dirt may be stripped off, a Beatle showered (9)
I believe the answer is:
ingrained
'as dirt may be' is the definition.
(dirt may be ingrained or embedded)
'stripped off a beatle showered' is the wordplay.
'stripped off' indicates the central letters (the outer letters are stripped off).
'a beatle' becomes 'Ringo' (Ringo Starr).
'showered' becomes 'rained' (showers of rain).
The middle letters of 'ringo' are 'ing'.
'ing'+'rained'='INGRAINED'
(Other definitions for ingrained that I've seen before include "Deep-dyed" , "Dine in rag (anag.)" , "Deep-rooted" .)