'Grey's Anatomy' Star Jesse Williams Says Donald Trump's 'Pig'

Jesse Williams had some words for Donald Trump ... none flattering.

We got the "Grey's Anatomy" star and civil rights activist heading into "The Daily Show" Wednesday in NYC, and asked how Trump was doing.

Dude makes it clear where he stands.

Remember ... Jesse's the guy who won BET's Humanitarian Award last year and rocked the house with his words.