dispatchyoudaoicibaDictYouDict[dispatch 词源字典]
dispatch: [16] Dispatch appears to have been borrowed from Spanish despachar ‘expedite’, but its ultimate origins are not clear. The likeliest source of the Spanish word is Old French despeechier ‘set free’ (source of modern French dépêcher ‘hurry’), a compound verb formed from the prefix des- ‘un-’ and the verbal element -peechier ‘impede, hinder’, which is also represented in English impeach and goes back ultimately to Latin pedica ‘shackle’.

The semantic history of dispatch thus appears to be ‘unshackle’, ‘set free’, ‘send away, get rid of’, and hence (with the notion of ‘freeing from restraint’) ‘send away quickly’. (The currency of the alternative spelling despatch is due to its occurrence in Dr Johnson’s Dictionary 1755.)
=> impeach[dispatch etymology, dispatch origin, 英语词源]
dispatch (v.)youdaoicibaDictYouDict
1510s, "to send off in a hurry," from a word in Spanish (despachar "expedite, hasten") or Italian (dispacciare "to dispatch"). For first element, see dis-. 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. Meaning "to get rid of by killing" is attested from 1520s. Related: Dispatched; dispatching. As a noun, from 1540s, originally "dismissal;" sense of "a message sent speedily" is first attested 1580s.