IPA: //ˈnæstiəst//
KK: /ˈnæstiɪst/
The most unpleasant or offensive in nature or behavior.
The nastiest comment I received was completely uncalled for.
Comparative: nastier
Superlative: nastiest
Nastiest → It is formed from "nasty" (originating from Middle English *nasti*, meaning unpleasant or offensive) and the superlative suffix "-est" (meaning most). The word "nastiest" means the most unpleasant or offensive.
Think of the word 'nasty' which means unpleasant, and remember that 'nastiest' refers to the most unpleasant thing.