Swell with blood (7)
I believe the answer is:
engorge
'swell with blood' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for engorge that I've seen before include "Swell with blood, water, etc" , "Overeat" , "Cause to swell with fluid" , "Eat ravenously" , "Congest with blood - eat greedily" .)