Where does “express” come from?

Express comes from French exprès, derived from Latin ex- (out) combined with a root ultimately tracing to Proto-Indo-European per-.

express (English): Moving or operating quickly, as a train not...

Definitions

express traces back through 3 separate lines of ancestry.

Step	Language	Word	Meaning
1	French	exprès	express
2	Latin	expressus	squeezed
3	Latin	exprimere	second-person singular future passive indicative...
4	Latin	ex-	out, away; throughout; thoroughly
5	Latin	e	The name of the letter "E"; out of, from
6	Latin	ex	A name of the letter "X"; out of, from
7	Latin	commūnicō	to impart, share
8	Latin	commūnis	common, commonplace, ordinary, general, universal, shared, shared alike, of both sides, belonging to two or more together
9	Old Latin	com(m)oinis	—
10	Proto-Italic	kommoinis	common
11	Proto-Indo-European	ḱom-moy-ni-	held in common
12	Proto-Indo-European	ḱóm	beside, near, by, with
13	Proto-Indo-European	ḱe	Deictic particle, here; Post-positional...
14	Middle English	kyt	—
15	German	kitt	putty certain kinds of cement used for fixing e.g. window panes
16	Old High German	kuti	—
17	Proto-West Germanic	kwidu	gum, resin
18	Proto-Germanic	kweduz	resin
19	Proto-Indo-European	gʷet-	resin, gum; to say, speak
20	Proto-Indo-European	gū-	to bend; curve; arch; vault; to bow, bend, arch,...

Step	Language	Word	Meaning
1	Latin	expressare	—
2	Latin	pressare	present active infinitive of pressō; to apply;...
3	Latin	presso	I press, squeeze; inflection of pressus: ##...
4	Latin	pressus	pressed, having been pressed, squeezed;...
5	Latin	premere	second-person singular future passive indicative...
6	Latin	premo	I press; I pursue
7	Proto-Indo-European	pres-	to press
8	Proto-Indo-European	per-	before, in front; first; to go through
9	Proto-Indo-European	pr̥tós	passed , crossed

Step	Language	Word	Meaning
1	Old French	espresser	—