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!!!
When someone enters a conversation by blurting something which they think is funny or appropriate to the conversation, but which completely kills the previously enjoyable conversation.
Example 1: Person 1: You slagging me!?
Person 2: Yeah! And!?
Person 1: Do you wanna fight!?
Person 3: Ooh, shit's going down!
(Person 1 and Person 2 leave because of Person 3's un-deahlifying comment).
Example 2: Person 1: Story, lads!?
Person 2: Awh, deahly like, wha!?
Person 3: Hello, guys.
(Person 3 has just un-deahlified the conversation).