1. A sniblet is a very small amount of something that can't be noticed at first sight. Ex. It could be a decrease in liquid, food or even a decrease in sand.
2. Secretely taking a small amount or object which is unnoticable.
3. Secretely taking a small amount or object which is happening in present tense.
A niblet of shit.
A small kernel or morsel of turd commonly found in the underpants after an unexpected shart.
Less commonly occuring after taking a shit and failing to completely pinch off the last stubborn nugget. Even cursory wiping typically removes this variety, but in rare cases this pinch-pirate will subsequently (and apparently randomly) release itself to be discovered in the briefs at a later time as a shiblet.
When entangled in ass-hair, may also be referred to as a klingon or dingleberry - though a free, unobstructed turd kernel discoverred in the tighty-whiteys is always referred to as a shiblet.
"Wot's this? A shiblet in my gonch? That ripper didn't feel wet... huh, I guess I must've sharted."
Bob: "Dude, I just found a ball of hash on the floor, let's party!"
Jon: "That's a shiblet man, don't smoke it! I found that rolling around in my gooch last Friday and flicked it at the ceiling... it must've fallen down."