おそらくPIE*dheu（塵、煙）が語源で、語源的にはdust（塵）、dull（鈍い）と同じ。 go off the beaten track（道を外れる）、perch（止まり木）、go with the flow（流れに身を任せる）、dwell（住む）の派生語。
英語の語源
dwell
dwell: [OE] Dwell has changed its meaning remarkably over the centuries. In Old English it meant ‘confuse, lead astray’. It goes back to a Germanic base *dwel-, *dwal-, *dwul-, which also produced Old English dwola ‘error’, Gothic dwals ‘foolish’, and Old High German gitwelan ‘be stunned’, and beyond that to Indo-European *dhwel-, source of Greek tholós ‘dirt’ and Irish dall ‘blind’.
Already by the end of the Old English period, ‘lead astray’ had progressed to ‘hinder, delay’, probably under the influence of the related Old Norse dvelja ‘delay’, and this subsequently developed through ‘linger’ to (in the 13th century) ‘make one’s home in a place’.
dwell (v.)
Old English dwellan "to mislead, deceive," originally "to make a fool of, lead astray," from Proto-Germanic *dwelan "to go or lead astray" (cognates: Old Norse dv?l "delay," dvali "sleep;" Middle Dutch dwellen "to stun, make giddy, perplex;" Old High German twellen "to hinder, delay;" Danish dvale "trance, stupor," dvaelb?r "narcotic berry," source of Middle English dwale "nightshade"), from PIE *dhwel-, extended form of root *dheu- (1) "dust, cloud, vapor, smoke" (and related notions of "defective perception or wits").
Related to Old English gedweola "error, heresy, madness." Sense shifted in Middle English through "hinder, delay," to "linger" (c. 1200, as still in phrase to dwell upon), to "make a home" (mid-13c.). Related: Dwelled; dwelt; dwells.
例文
1. I shut out the memory which was too painful to dwell on.
私はもうそんなつらい昔のことを思い出さない。
2.It does not do to dwell on dreams and forget to live.
幻の夢に溺れて現実を忘れる生活は、何の役にも立たない。
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3.Sometimes his mind would dwell on the horrors he had been through.
彼は時々経験した様々な恐怖を考えている。
4.It 's morbid to dwell on cemeteries and such like.
墓地やそのようなことをこまめに話すのは病的である。
5.A great number of water fowls dwell on the island.