illy

In US hip-hop slang, 'illy' means cool, fresh, or impressively skilled -- a positive intensifier with roots in 1990s East Coast rap culture. The word played on the negative 'ill' being flipped into a positive (a common semantic reversal in hip-hop). As an adverb it can also mean badly or poorly, but the positive hip-hop sense is the more culturally salient meaning.

Illy operates in two opposite registers. As a standard adverb, it means badly or poorly — a slightly archaic form of 'ill' used adverbially. But in US hip-hop slang, particularly from the late 1980s and 1990s, 'illy' flipped to mean cool, fresh, or excellent — following the same positive-negative inversion pattern seen in 'bad', 'sick', and 'nasty'. In hip-hop contexts it carries connotations of skill and style, often applied to a rapper's flow or a particularly sharp outfit. Context is everything with this one.

Badly; poorly.

(US, chiefly, hip-hop) cool, fresh.