A sheep I included in account in Biblical language (7)
I believe the answer is:
aramaic
'biblical language' is the definition.
(I've seen this before)
'a sheep i included in account' is the wordplay.
'sheep' becomes 'ram' (male sheep).
'included in' indicates putting letters inside.
'account' becomes 'ac' (abbreviation for account).
'i' put within 'ac' is 'aic'.
'a'+'ram'+'aic'='ARAMAIC'
'in' is the link.
(Other definitions for aramaic that I've seen before include "Biblical language" , "Language of Near East" , "Ancient Semitic language" , "Semitic language spoken in New Testament times" , "Near Eastern language" .)