Significant

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late 16th century (in significant (sense 2)): from Latin significant- ‘indicating’, from the verb significare (see signify).

wiktionary

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From Latin significans, present participle of significare, from signum(“sign”) + ficare(“do, make”), variant of facere.

etymonline

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significant (adj.)

1570s, "having a meaning," from Latin significantem (nominative significans, present participle of significare "make known, indicate" (see signify). Earlier in the same sense was significative (c. 1400). Often "having a special or secret meaning," hence "important" (1761). Related: Significantly. Significant figure is from 1680s. Significant other (n.) attested by 1961, in psychology, "the most influential other person in the patient's world."