Dog delivering bite, after jumping up, that is (4,3)
I believe the answer is:
shar-pei
'dog' is the definition.
(I've seen this before)
'bite after jumping up that is' is the wordplay.
'bite' becomes 'sharp' (I am not sure about this - if you are sure you should believe this answer much more).
'after' means one lot of letters go next to another.
'jumping up' says the letters should be written in reverse (in a down clue, letters go up).
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'ie' in reverse letter order is 'ei'.
'sharp'+'ei'='SHAR-PEI'
'delivering' is the link.
Can you help me to learn more?
(Other definitions for shar-pei that I've seen before include "Chinese dog breed" , "Chinese dog; I phrase (anag.)" .)