quantum

The smallest amount of a physical quantity that can exist independently, especially a discrete quantity of electromagnetic radiation.

This amount of energy regarded as a unit.

A quantity or amount.

A specified portion.

Something that can be counted or measured.

A unit of acetylcholine, released at the synaptic cleft of a neuromuscular junction.

Relating to or based upon quantum theory.

That which has quantity; a concrete quantity.

A prescribed, proper, or sufficient amount.