in a way that must be obeyed:
Alcohol is strictly forbidden on school premises.
The ban on hunting is not strictly enforced.
exactly and completely:
That isn't strictly true.
used to say that something is true if you are going to be very exact and correct about it:
Strictly speaking, spiders are not insects.
only for a particular person, thing, or purpose and no one else:
This is strictly between us. Nobody else must know.