From Latin quōmodo (“In what way?”).

quomodo (plural quomodos)

1. (obsolete) The means, way, or method (of doing something).
   • 1749, Henry Fielding, “The Conclusion of the foregoing Adventure”, in The History of Tom Jones, a Foundling, volume III, London: A Millar, , →OCLC, book VII, page 132:

     In a Word, to hint at no more Reaſons for his Conduct, Mr. Northerton was deſirous of departing that Evening, and nothing remained for him but to contrive the Quomodo, which appeared to be a Matter of ſome Difficulty.

• quō modō
• cōmodo, cōmo (non-literary, epigraphy and manuscripts)
• quōmo (non-literary, 4-5th c. CE manuscripts)
• quōmodī, comdī, quāmodī, quīmodī (nonstandard)

Univerbation of quō (“what”, abl. sg.) +‎ modō (“manner, way”, abl. sg.). /kō-/ variants first attested in Pompeii. /d/-less variants (through allegro-speech consonant elision or some kind of metanalysis) securely attested from mid-1st c. CE onwards. Forms in /-ī/ likely by analogy with cuius-/eiusmodī.

• (Classical Latin) IPA^(key): ,
• (modern Italianate Ecclesiastical) IPA^(key):
• Note: the final vowel scanning as long is common in tmesis, variable in scenic verse, once in hendecasyllables (Catullus 10.7).

quōmodo (not comparable)

1. (interrogative) in what manner or way?; how?
   1. (rhetorical) how is that possible (that)?
2. in what condition or circumstances? how?

   Quōmodo tibi rēs sē habet? ― How's your business going along?

   1. Used in warnings, threats and exclamations.

      At scīn' quōmodo? ― You know what I'm gonna do?

      Sed quōmodo dissimulabat! ― But how he was faking it!

3. (relative) in the same manner or way as; how, like
   1. (with the correlatives sīc or ita) in the manner in which, just as, just like
      • 1 cent. BC (curse tablet) CIL I² 1012 = CIL VI 140 = SIAtt-1, p. 82 = ILLRP 1144 = D 8749 = DefTab 139 = Kropp-01-04-04-03:

        Quōmodo mortuos, quī istīc sepultus est nec loquī nec sermōnāre potest, seic Rhodinē apud M(ārcum) Licinium Faustum mortua sit nec loquī nec sermōnāre possit

        Just like the dead man who's been buried here cannot speak nor talk , so may Rhodine be dead for Marcus Licinius Faustus, nor be able to speak or talk .

   2. (with subjunctive, introducing final clauses) by means of which, using which

• (interrogative): ut, quī, quemadmodum
• (relative): (ita) ut, quemadmodum, sīcut

• quōmodo et

(See also quōmodo et.)

• >? Friulian: cemût
• → English: quomodo

Reflexes of the late form cōmo:

• “quōmodo” on page 1727 of the Oxford Latin Dictionary (2nd ed., 2012)
• “quōmodō̆” in volume 8, column 1287, line 38 in the Thesaurus Linguae Latinae (TLL Open Access), Berlin (formerly Leipzig): De Gruyter (formerly Teubner), 1900–present
• Daniela Urbanová (2016) “Alcune particolarità della comparazione (quomodo – sic, quemadmodum – sic, ita uti – sic) in latino volgare, con particolare attenzione alle defixiones”, in Graeco-Latina Brunensia‎, number 2, →DOI, →ISSN, pages 329–343

• “quomodo”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• quomodo in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
• Carl Meißner, Henry William Auden (1894) Latin Phrase-Book‎, London: Macmillan and Co.
  • to detail the whole history of an affair: ordine narrare, quomodo res gesta sit
    
  • as the proverb says: ut or quod or quomodo aiunt, ut or quemadmodum dicitur