expressyoudaoicibaDictYouDict[express 词源字典]
express: [14] Something that is expressed is literally ‘pressed out’. The word comes via Old French from Vulgar Latin *expressāre, a compound verb formed from the prefix ex- ‘out’ and pressāre ‘press’. Its meaning developed metaphorically from ‘press out’ to ‘form by pressure’ (presumably applied originally to modelling in clay or some similar substance, and subsequently to sculpture and then painting), and finally to ‘make known in words’.

The Vulgar Latin verb was in fact moving in on territory already occupied by its classical Latin forerunner exprimere (source of French exprimer ‘express’ and perhaps of English sprain [17]). The past participle of this was expressus, used adjectivally for ‘prominent, distinct, explicit’. Old French took it over as expres and passed it on to English in the 14th century.

By now its meaning was moving towards ‘intended for a particular purpose’, and in the 19th century it was applied to ‘special’ trains (as in ‘football specials’). It did not take long, however, for this to slip via ‘train for people wanting to go to a particular place, and therefore not stopping anywhere else’ to ‘fast train’. Hence the modern sense of express, ‘fast’, was born.

=> espresso, press, sprain[express etymology, express origin, 英语词源]
express (v.1)youdaoicibaDictYouDict
late 14c., "represent in visual arts; put into words," from Old French espresser, expresser "press, squeeze out; speak one's mind" (Modern French exprimer), Medieval Latin expressare, frequentative of Latin exprimere "represent, describe, portray, imitate, translate," literally "to press out" (source also of Italian espresso); the sense evolution here perhaps is via an intermediary sense such as "clay, etc., that under pressure takes the form of an image," from ex- "out" (see ex-) + pressare "to press, push," from Latin premere (see press (v.1)). Related: Expressed; expresses; expressing.
express (adj.)youdaoicibaDictYouDict
late 14c., "stated explicitly, not implied, clearly made known" from Old French espres, expres (13c.), from Latin expressus "clearly presented, distinct, articulated precisely," past participle of exprimere (see express (v.)). Also late 14c. as an adverb, "specially, on purpose;" it also doubled as an adverb in Old French. An express train (1841) originally was one that ran to a certain station.
express (v.2)youdaoicibaDictYouDict
"to send by express service," 1716, from express (n.).
express (n.)youdaoicibaDictYouDict
1610s, "special messenger," from express (adj.). Sense of "business or system for sending money or parcels" is by 1794.