Initially approve consultation regarding emergency measure (4)
I believe the answer is:
acre
'measure' is the definition.
(acre is a kind of measure)
'initially approve consultation regarding emergency' is the wordplay.
'initially' indicates taking the first letters.
The first letters of 'approve consultation regarding emergency' is 'ACRE'.
(Other definitions for acre that I've seen before include "region of ground" , "Square measure of land" , "in Western Brazil" , "Imperial land measure" , "Four thousand, eight hundred and forty square yards" .)