More thick than your averagethicc. An exclamation to be made shortly after witnessing a booty of astronomical proportions. Used often by homosexuals to describe other men, or by supposedly straight men in jest.
Gay 1: you see bill at the club the other day?
Gay 2: Ye boy he was looking goofy thicc.
A way of saying "one thicc boi". The "un" is the masculine indefinite article, meaning "a", from the Spanish language. "Thicc boi" is from the English language, and when combining these two phrases, makes a Spanglish sentence. This is a better way to say "one thicc boi" and is, from experience, more likely to get laughs. Sometimes you can say "un hella thicc boi" but that can be a bit over the top.
(Eighth graders learning about U.S. History)
Person 1: (whispers) Washington was un thicc boi, am I right?
Person 2: (Trying to muffle their laughter) Hell yeah!!!