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.