Allow Bernstein to lie regularly (7)
I believe the answer is:
entitle
'allow' is the definition.
(thesaurus)
'bernstein to lie regularly' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'bernstein'+'to'+'lie'='bernsteintolie'
The alternate letters of 'bernsteintolie' are 'ENTITLE'.
(Other definitions for entitle that I've seen before include "Licence" , "term" , "Style; give right to" , "Give one the right - name" , "Name, authorise" .)