When the vibe/mood/aura of a room/place seems uneasy and out of the ordinary, the air is heavy and something feels wrong. It commonly foreshadows that something terrible is about to happen.
The term was heavily popularized in 2017 when the game DDLC (Doki Doki Literature Club) was released, and one of the characters (Yuri) uses it.
“Stagnating air is common foreshadowing that something terrible is about to happen” -Yuri2017
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.
A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.
I had a trucker's tan after driving for 10 straight hours on a sunny day.