For them, it's just a COINCIDENCE/ACCIDENT that it begins with 'dis. But most English speakers don't have that parallel. I happen to speak French, so I see dépêcher and empêcher: to remove barriers (for speed in sending something) or to put in barriers (to prevent).

BUT English borrowed it as a single piece English speakers do NOT TODAY perceive the 'dis' as a prefix, the way they do in displease, dissent, discover, dislike, etc. A ship prefix is a combination of letters, usually abbreviations, used in front of the name of a civilian or naval ship that has historically served. 对不起。'Dis' WAS a prefix in Italian and Spanish in the 1500s, in THOSE languages. As a noun, from 1540s, originally 'dismissal ' sense of 'a message sent speedily' is first attested 1580s. Meaning 'to get rid of by killing' is attested from 1520s. The exact source of the second element has been proposed as Vulgar Latin *pactare 'to fasten, fix' or *pactiare, or as Latin -pedicare 'to entrap' (from Latin pedica 'shackle ' see impeach) and the Spanish and Italian words seem to be related to (perhaps opposites of) Old Provençal empachar 'impede.' See OED for full discussion. For first element (as I said, it _was_ a prefix in the Indo-European languages English took it from), see dis. Here's what 'etymology online' says: 1510s, 'to send off in a hurry,' from a word in Spanish (despachar 'expedite, hasten') or Italian (dispacciare 'to dispatch'). Well, it was once (has been) a prefix, but not in English.

For them, it's just a COINCIDENCE/ACCIDENT that it begins with 'dis.' BUT English borrowed it as a single piece English speakers do NOT TODAY perceive the 'dis' as a prefix, the way they do in displease, dissent, discover, dislike, etc.

Dispatch meaning prefix