Trying to excise mass: no significant growth (7)
I believe the answer is:
sapling
'growth' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for sapling that I've seen before include "Little tree" , "Lapsing into a young tree" , "Poetic youth" , "Baby tree" , "Young slender tree" .)