quantum — ODE

quantum /ˈkwɒntəm

▸ noun

(plural quanta /ˈkwɒntə

1 Physics a discrete quantity of energy proportional in magnitude to the frequency of the radiation it represents.

▪ an analogous discrete amount of any other physical quantity, such as momentum or electric charge.

▪ Physiology the unit quantity of acetylcholine released at a neuromuscular junction by a single synaptic vesicle, contributing a discrete small voltage to the measured end-plate potential.

2 a required or allowed amount, especially an amount of money legally payable in damages:

the court must determine the quantum of compensation due.

▪ a share or portion:

each man has only a quantum of compassion.

– ORIGIN mid 16th century (in the general sense ‘quantity’): from Latin, neuter of quantus (see quantity). Sense 1 dates from the early 20th century.