Certainly, affirmative (3)
I believe the answer is:
yes
I believe this is a double definition.
'certainly' is the first definition.
(both can be used to answer in the affirmative)
'affirmative' is the second definition.
(affirmative answer word)
(Other definitions for yes that I've seen before include "I agree" , "Positive response" , "3 across" , "Pro vote" , "Positive reply" .)