doubt

Etymology tree

Proto-Italic *du(i)βwos

Latin *dubosdenom.

Latin dubō

Proto-Indo-European *-tós

Proto-Italic *-tos

Latin -tus

Proto-Indo-European *-h₂

Proto-Indo-European *-éh₂

Proto-Indo-European *-yéti

Proto-Indo-European *-eh₂yéti

Proto-Indo-European *-h₂tiinflu.

Proto-Italic *-ājō

Proto-Italic *-āō

Latin -ō

Latin -tō

Latin -itō

Latin dubitō

Old French doterbor.

Middle English douten

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Old French doter

Old French doutebor.

Middle English doute

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English dubiousinflu.

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Latin dubitōinflu.

English doubt

The verb is derived from Middle English douten (“to doubt, fear, worry”) [and other forms], from Old French douter, doter, duter (compare Middle French doubter), from Latin dubitāre (“to be uncertain, doubt; to hesitate, waver in coming to an opinion; to consider, ponder”); the further etymology is uncertain, but one theory is that dubitō may be derived from dubius (“fluctuating, wavering; doubtful, dubious, uncertain”), from duhibius (“held as two”), from duo (“two”) (ultimately from Proto-Indo-European *dwóh₁ (“two”)) + habeō (“to have, hold”) (possibly ultimately from Proto-Indo-European *gʰeh₁bʰ- (“to grab, take”)). Spelling reformers of the early modern period added the letter b to reflect the Latin root dubitō, but it has never been pronounced in English.

The noun is derived from Middle English dout, doute (“uncertainty, hesitation; questionable point; anxiety, fear, reverence”) [and other forms], from Old French doute, dote, dute (“uncertain feeling, doubt”), from doter, douter, duter (“to doubt, fear”) (compare Middle French doubter; modern French douter (“to doubt, suspect”)); see further etymology above.

The ESL "question" sense is a semantic loan from Romance cognates: Portuguese dúvida, Spanish duda, Catalan dubte, French doute, Italian dubbio and others, which can all mean "question".

Displaced Old English twēo (“doubt”) and twēoġan (“to doubt”).