Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
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Ancient Greek ἄγνωτος
Ancient Greek ἀ- (affix)
Ancient Greek γιγνώσκω (mention)
Ancient Greek ἀγνώς (mention)
Proto-Indo-European *ǵneh₃- (root)
Latin īgnōtus (cognate)

English agnotology (mention)
Ancient Greek ἀγνώς (mention)
Latin ignotus (cognate)
Tocharian B aknātsa (cognate)
Tocharian A āknats (cognate)