Unanimous

google

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early 17th century: from Latin unanimus (from unus ‘one’ + animus ‘mind’) + -ous.

wiktionary

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From Latin ūnanimus(“of one mind”), from ūnus(“one”) +‎ animus(“mind”).

etymonline

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unanimous (adj.)

1610s, from Latin unanimus "of one mind, in union," from unus "one" (from PIE root *oi-no- "one, unique") + animus "mind, spirit" (see animus). Related: Unanimously.