quantity or amount

the least quantum of evidence.

a particular amount.

a share or portion.

a large quantity; bulk.

Physics .

the smallest quantity of radiant energy, equal to Planck's constant times the frequency of the associated radiation.

the fundamental unit of a quantized physical magnitude, as angular momentum.

sudden and significant

a quantum increase in productivity.

noun

allocation , allowance , dole , lot , measure , part , portion , quota , ration , share , split , amount , body , budget , bulk , corpus , quantity , sum , total , unit