Heavy Water 

D2O, 2 Deuterium, and 1 Oxygen atom. Deuterium is an isotope of hydrogen; it has one extra neutron in the nucleus. Neutrons are what add weight to an atom; this substance is called "Heavy Water" as compared to normal "Light Water." Heavy water exists is most all water, but only in very small amounts (1 in 20 million).

Heavy water is essential to nuclear power using non-enriched uranium. Without it, all uranium must be enriched before use. In WW-II, Hitler attacked Norway for it’s supply of heavy water.

"Heavy water aids in cooling nuclear reactors.

Heavy Water by Contraceptive SpongeBob April 17, 2006

heavy under water 

attractive female with a disproportianately large rear end

She's not a bad looker just kind of heavy under water though

heavy under water by GlennieB August 25, 2008

Cheeks 

An Irish phrase meaning shit, derived from ass
(Not to be confused with the literal description of one's buttocks)

"Did you hear the song Aylek$ dropped?"
"Hardly. Her music is absolute cheeks."

"My boyfriend say LaFlame is cheeks."
"Tell your boyfriend I said it's his mixtape that's cheeks."

Cheeks by thecartisan April 26, 2020

sans sheriff 

Lawless use of fonts or typography, with no regard to aesthetics or legibility

I'm putting this CV straight in the bin. Written totally sans sheriff.

sans sheriff by Jamarley July 3, 2019

Breadhead 

Someone who is addicted to obtaining money and building wealth. A money addict and fanatic. Breadheads often work more than one full-time job, and some even participate in illicit activities to "obtain the bread".

A breadhead is like a crackhead, but for money instead of crack.

Breadhead by 🅱️ U S 3 4 8 March 30, 2022

Stink lines

As seen in illustrations or cartoons: Wavy, vertical lines rising above a person, place or thing. Denotes a foul odor.

"You didn't put enough stink lines on your picture of the teacher."

Stink lines by Athene Airheart March 14, 2004

schmegegge 

Yiddish slang word meaning bullshit, baloney, hogwash, nonsense, crock of shit or hot air.

I don't buy the schmegegge about Morty sleeping with Moira.
His version of the story was pure schmegegge.
The whole schmegegge was made up to get Liz a little bit of attention.

schmegegge by budsbabe February 1, 2008