/kwon"teuhm/ , n. , pl. quanta /-teuh/ , adj.
n.
1. quantity or amount: the least quantum of evidence.
2. a particular amount.
3. a share or portion.
4. a large quantity; bulk.
5. Physics.
a. the smallest quantity of radiant energy, equal to Planck's constant times the frequency of the associated radiation.
b. the fundamental unit of a quantized physical magnitude, as angular momentum.
adj.
6. sudden and significant: a quantum increase in productivity.
[ 1610-20; n. use of neut. of L quantus how much ]