Thus

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Old English, of unknown origin.

wiktionary

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From Middle English thus, thous, thos, from Old English þus(“thus, in this way, as follows, in this manner, to this extent”), from Proto-West Germanic *þus(“so, thus”), perhaps originally from a variant of the instrumental form of this, related to Old English þȳs(“by this, with this”), Old Saxon thius(“by this, with this”). Cognate with Scots thus(“thus”), North Frisian al doz(“thus”), West Frisian dus(“thus”), Dutch dus(“thus, so”), Low German sus(“thus, hence”).

thus ( uncountable)

etymonline

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thus (adv.)

Old English þus "in this way, as follows," related to þæt "that" and this; from Proto-Germanic *thus- (source also of Old Saxon and Old Frisian thus, Middle Dutch and Dutch dus), from PIE *to-.