In here, there's not just a little drop (5)
I believe the answer is:
abyss
'in here there's not just a little drop' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for abyss that I've seen before include "great depth" , "gaping hole" , "crevasse" , "something rather deep" , "canyon?" .)