Old Norse guard taking in English examination (4,4)
I believe the answer is:
once over
'examination' is the definition.
(once-over is a kind of examination)
'old norse guard taking in english' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'norse' becomes 'N' (abbreviation in linguistics).
'guard' becomes 'cover'.
'taking in' is an insertion indicator.
'english' becomes 'E' (abbreviation).
'cover' enclosing 'e' is 'ceover'.
'o'+'n'+'ceover'='ONCE-OVER'
(Other definitions for once over that I've seen before include "inspection" , "quick read?" , "Quick survey" , "examination" .)