pressurize v.

late 14c., "suffering, anguish; act or fact of pressing on the mind or heart," from Old French presseure "oppression; torture; anguish; press" (for wine or cheeses), "instrument of torture" (12c.) and directly from Latin pressura "action of pressing," from pressus, past participle of premere "to press, hold fast, cover, crowd, compress" (from PIE root *per- (4) "to strike").

The literal meaning "act or fact of pressing" in a physical sense is attested in English from early 15c. The meaning "moral or mental coercing force, exertion of authority or influence" is from 1620s; the meaning "urgency, demand on one's time or energies" is from 1812. Scientific sense in physics, "force per unit area exerted over a surface and toward the interior" is from 1650s.

Pressure cooker "airtight vessel in which food is cooked in steam under pressure" is attested from 1915; figurative sense is from 1958. Pressure point of the skin is attested from 1876. Pressure-treated, of woods impregnated with a preservative fluid under pressure, is from 1911.

word-forming element used to make verbs, Middle English -isen, from Old French -iser/-izer, from Late Latin -izare, from Greek -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached.

The variation of -ize and -ise began in Old French and Middle English, perhaps aided by a few words (such as surprise, see below) where the ending is French or Latin, not Greek. With the classical revival, English partially reverted to the correct Greek -z- spelling from late 16c. But the 1694 edition of the authoritative French Academy dictionary standardized the spellings as -s-, which influenced English.

In Britain, despite the opposition to it (at least formerly) of OED, Encyclopaedia Britannica, the Times of London, and Fowler, -ise remains dominant. Fowler thinks this is to avoid the difficulty of remembering the short list of common words not from Greek which must be spelled with an -s- (such as advertise, devise, surprise). American English has always favored -ize. The spelling variation involves about 200 English verbs.

"cause a drop in the pressure of a gas in a certain space," 1944; see de- + pressurize. Related: Depressurized; depressurizing; depressurization.