IPA: /ˈnæti/
KK: /ˈnæti/
The most stylish or well-dressed; very neat and attractive in appearance.
He always wears the nattiest clothes to the party, impressing everyone with his style.
Comparative: nattier
Superlative: nattiest
Nattiest → It is formed from "natty" (from the 19th-century slang meaning stylish or neat) and the suffix "-est" (meaning most). The word "nattiest" means the most stylish or neat in appearance.
Think of someone being the "most stylish" or "neat" — that's what nattiest means.