Used to describe that something is expected to happen but has not for the moment.
Learner Tips: With mouth morpheme TH! Without this proper mouthing, it means LATE.
This usage has multiple meanings in contexts in ASL.
One is "something expected to happen but has not for the moment".
Another is "no, something has not happened" with no indication or intention to complete or happen. E.g. Did you finish your homework?
Third, another meaning is that something has never happened." It didn't happen. E.g. A mother asks her son in ASL (translated as), "My $100 bill is missing in my purse. Did you take my $100 bill from my purse?" The son honestly replies, no. Since the mother and her son live alone, she asks again. The son insisted that sign NO-NEVER-DID! (as the gloss NOT-YET is a bad gloss for this context).
Review 101 words. Refresher.