About to jump at some meat (4)
I believe the answer is:
chop
'some meat' is the definition.
(chop is a kind of meat)
'about to jump' is the wordplay.
'about' becomes 'c' (abbreviation for 'circa').
'to jump' becomes 'hop' (hopping is a kind of jumping).
'c'+'hop'='CHOP'
'at' is the link.
(Other definitions for chop that I've seen before include "Use a cleaver" , "Hew" , "Cut of meat; hack" , "Dissect" , "Chinese seal" .)