A positive indication (3)
I believe the answer is:
nod
This might be a double definition.
'a positive' is the first definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'indication' is the second definition.
(thesaurus)
Can you help me to learn more?
(Other definitions for nod that I've seen before include "Gesture of agreement" , "may get gesture of approval" , "Indicate agreement (or sleepiness!)" , "Affirmative action?" , "Go to sleep in this land" .)