Kind of snake
I think it could be either:
'kind of snake' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for adder that I've seen before include "danger in the countryside" , "An arithmetic snake" , "Mathematical reptile" , "accountant?" , "calculator?" .)
'kind of snake' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for coral that I've seen before include "Marine polyps, often forms reefs" , "Reef-forming sea life" , "Reef-forming skeletons" , "Basic material of South Sea islands" , "Calcareous skeletal remains forming reefs" .)