Originated by singer of Baltimore, Maryland band Rest Among Ruins, the term 'nt negates whatever word or phrase it is added to.
'nt's are mathematically sensitive. Therefore an even amount of 'nt's added to a word or phrase causes a double negation.
Cool'nt = not cool
Dude, I can't wait to go to class later'nt = Dude, I can't wait to NOT go to class later
That was sweet'nt'nt = That was sweet!