Rolling-Block
Not sure if that was your question.
A single gear is called a pinion.
A single egg is called an ovum or oocyte.
Her first single was called Hallelujah.
A single eye glass is called a monocle.
A single block of stone is called a monolith.
a single winged plane is called a monoplane
A single character play is called a monologue. It features a single actor speaking alone on stage.
a single celled organism is called unicellular an example is yeast
If a single cell is living on its own it is called a single-celled organism. There are millions of single-celled organisms alive today.
Selena Gomez's new single is called Who Says
A single unit of quantum is called a quantum or a quantum of energy.
A single point on a computer monitor called pixel.