A to-do? Yes (3)
I believe the answer is:
ado
This might be a double definition.
'a to-do?' is the first definition.
(thesaurus)
'yes' is the second definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
Can you help me to learn more?
(Other definitions for ado that I've seen before include "flapping" , "Pother" , "stew is provided" , "'Much ... About Nothing, Shakespeare play (3)'" , "carry-on" .)