Artificial ice plant (8)
I believe the answer is:
shamrock
This might be a double definition.
'artificial ice' is the first definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'plant' is the second definition.
(shamrock is a kind of plant)
Can you help me to learn more?
(Other definitions for shamrock that I've seen before include "Sign of first part of 10 [IRISH [SEA]]" , "Symbol of Ireland" , "symbolic of Ireland" , "Clover-like plant" , "Mash cork into the emblem" .)