D defs.my
Entry 2 senses Webster, 1913

Quantum

/kwän'-təm/ · Quan·tum · IPA /ˈkwɑntəm/
01 n. Quantity; amount.
pl. Quanta ((#))
  1. 1.
    Quantity; amount.
  2. 2.
    A definite portion of a manifoldness, limited by a mark or by a boundary.(Math.)
Phrases & compounds
‖Quantum meruit — a count in an action grounded on a promise that the defendant would pay to the plaintiff for his service as much as he should deserve.
‖Quantum sufficit — a sufficient quantity; -- abbreviated q. s. in pharmacy.
‖Quantum valebat — a count in an action to recover of the defendant, for goods sold, as much as they were worth.