From Proto-Hellenic *artʰmós, from Proto-Indo-European *h₂er- (“to fit; to put together”) + -θμός (-thmós). Semantically merged with the etymologically older ἀρτύς (artús), which is from the same root but with a different suffix.
ἀρθμός • (arthmós) m (genitive ἀρθμοῦ); second declension
| Case / # | Singular | Dual | Plural | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nominative | ὁ ἀρθμός ho arthmós |
τὼ ἀρθμώ tṑ arthmṓ |
οἱ ἀρθμοί hoi arthmoí | ||||||||||
| Genitive | τοῦ ἀρθμοῦ toû arthmoû |
τοῖν ἀρθμοῖν toîn arthmoîn |
τῶν ἀρθμῶν tôn arthmôn | ||||||||||
| Dative | τῷ ἀρθμῷ tôi arthmôi |
τοῖν ἀρθμοῖν toîn arthmoîn |
τοῖς ἀρθμοῖς toîs arthmoîs | ||||||||||
| Accusative | τὸν ἀρθμόν tòn arthmón |
τὼ ἀρθμώ tṑ arthmṓ |
τοὺς ἀρθμούς toùs arthmoús | ||||||||||
| Vocative | ἀρθμέ arthmé |
ἀρθμώ arthmṓ |
ἀρθμοί arthmoí | ||||||||||
| Notes: |
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