At Sodom regularly? Excessively! (3)
I believe the answer is:
too
'excessively' is the definition.
(synonyms)
'at sodom regularly?' is the wordplay.
'regularly?' indicates alternate letters (regularly take one letter, leave next etc.).
'at'+'sodom'='atsodom'
The alternate letters of 'atsodom' are 'TOO'.
(Other definitions for too that I've seen before include "To a greater than desirable extent" , "Also; overly" , "On top - also" , "Furthermore" , "Unduly" .)