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").
Literal meaning "act or fact of pressing" in a physical sense is attested from early 15c. Meaning "moral or mental coercing force" is from 1620s; meaning "urgency" is from 1812. Scientific sense in physics is from 1650s. Pressure cooker is attested from 1915; figurative sense is from 1958. Pressure point is attested from 1876. Pressure-treated, of woods, is from 1911.