What is the meaning of Natty?

Smart and fashionable.

Knotty.

Natural, as opposed to steroid enhanced.

Someone whose muscle gains are natural and not aided by the use of steroids.

National.

A national championship.

Abbreviation of natty dreadlocks.

dreadlocked, knotty, nappy

to grow dreadlocks; to grow locks

Source: wiktionary.org