σθένος

Unknown.^[1] The cluster /stʰ/ is unusual for Ancient Greek terms inherited from Proto-Indo-European. However several hypotheses for an Indo-European derivation exist:

• Cognate with Old English stīþ (“hard, cruel, violent”) (English stith (“stiff, hard”)), from Proto-Indo-European *stHen-.^[2] This assumes that a sequence *-TH- could result in Greek -θ- (-th-), which is disputed.

• Cognate with Proto-Germanic *swinþaz (“strong”) (and possibly also *sundaz (“healthy”)) through the root of *segaz (“victory”);^[2] from a Proto-Indo-European *séǵʰwr̥, *sǵʰwén- (“power, overpowering”) which is inferred from various derivatives.

• From the zero-grade *sgʷʰ- of a root *segʷʰ- (“to be strong”), whence also Sanskrit सघ्नोति (saghnóti, “to be a match for, be equal to (a task)”), क्षम् (kṣam, “to endure, resist; forgive”) and Avestan 𐬀𐬰𐬔𐬀𐬙𐬀 (a-zg-ata, “irresistible (?)”), plus an uncertain suffix *-énos.^[1]

The latter two both assume Proto-Hellenic *skʷʰénos.

This etymology is incomplete. You can help Wiktionary by elaborating on the origins of this term.

σθένος • (sthénos) n (genitive σθένεος or σθένους); third declension

1. strength, might, power

• → Greek: σθένος (sthénos)
• ⇒ Translingual: Sthenopsis

• “σθένος”, in Liddell & Scott (1940) A Greek–English Lexicon, Oxford: Clarendon Press
• σθένος in Bailly, Anatole (1935) Le Grand Bailly: Dictionnaire grec-français, Paris: Hachette
• σθένος in Cunliffe, Richard J. (1924) A Lexicon of the Homeric Dialect: Expanded Edition, Norman: University of Oklahoma Press, published 1963
• Woodhouse, S. C. (1910) English–Greek Dictionary: A Vocabulary of the Attic Language‎^[1], London: Routledge & Kegan Paul Limited.
  • force idem, page 335.
  • lustiness idem, page 505.
  • might idem, page 528.
  • power idem, page 630.
  • strength idem, page 824.
  • thews idem, page 865.
  • vigour idem, page 952.

Borrowed from Ancient Greek σθένος (sthénos).

• IPA^(key): /ˈsθe.nos/
• Hyphenation: σθέ‧νος

σθένος • (sthénos) n

1. moral or emotional strength, might, power
2. (chemistry) valence, valency
3. (grammar, linguistics) valency (number of grammatical arguments a verb can take)

• σθένος, in Λεξικό της κοινής νεοελληνικής [Dictionary of Standard Modern Greek], Triantafyllidis Foundation, 1998 at the Centre for the Greek language