Often said when you second guess your (or someone else's) initial impression of something/someone.
Usually, I find him ugly, but today he's smokin' hot. Must be the lighting.

She looked hot on instagram, but then I met her IRL. Must've been the lighting.

Person A (who is overweight): I look so skinny today.
Person B: It must be the lighting.
by libelula_안녕 July 17, 2018
Get a must be the lighting mug for your fish Julia.
The one house that just smells so bad it makes you want to kill yourself
MAN, Peytons house smells like shit. I’m about to just call it the must dungeon
by D1CK CHEESE March 07, 2021
Get the must dungeon neck gaiter and mug.
Similar to a Crop Duster, but different in that a Must Duster always leaves behind a musty smell, like old mold, or like a dusty gust of penicillin spores fresh off an expired loaf of bread, but instead out of the Must Duster's rear.
Our office Must Duster walked by and sprinkled us with her moldy dust, thus creating a psynchronized nose covering to block out the spores of her un-welcomed scent.
by siamese6 August 15, 2007
Get a Must Duster mug for your bunkmate Sarah.
old dirty stanky dont take no kind of bath looking person
Man u betta tell that girl to get her musted tail on somewhere!!!!
by jazzy jazz July 15, 2008
Get a musted tail on mug for your buddy James.