An Etymological Dictionary of Astronomy and Astrophysics

Math.: To restrict a variable quantity to discrete values rather than to a continuous set of values.
Physics: To change the description of a physical system from classical to quantum-mechanical, usually resulting in discrete values for observable quantities, as energy or angular momentum.

Etymology (EN): From quant(um) + → -ize.

Etymology (PE): From kuântom, → quantum, + -idan infinitive suffix.