Where Neagh is, lough, duck found therein? (3)
I believe the answer is:
nil
'where neagh is lough duck found therein?' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for nil that I've seen before include "Latin zero" , "There's nothing left" , "You get nothing" , "Nothing, zero" , "0" .)