Etymology
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swastika (n.)

Greek cross with arms bent at right angles, 1871 (in English specifically as emblem of the Nazi party from 1932), from Sanskrit svastika-s, literally "being fortunate," from svasti-s "well-being, luck," from su- "well" (from PIE *(e)su- "good," originally a suffixed form of root *es- "to be") + as-, root of asti "(he) is," which also is from PIE root *es- "to be."

Also known as gammadion (Byzantine), cross cramponnee (heraldry), Thor's hammer, and, perhaps, fylfot. Originally an ancient cosmic or religious symbol thought to bring good luck. Use in reference to the Nazi emblem first recorded in English in 1932. The German word was Hakenkreuz, literally "hook-cross."

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Hakenkreuz (n.)
1931, proper German name for the Nazi swastika (q.v.), literally "hook-cross," from Old High German hako "hook," from Proto-Germanic *hoka-, from PIE root *keg- "hook, tooth."
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*es- 

Proto-Indo-European root meaning "to be."

It forms all or part of: absence; absent; am; Bodhisattva; entity; essence; essential; essive; eu-; eucalyptus; Eucharist; Euclidean; Eudora; Eugene; eugenics; eulogy; Eunice; euphemism; euphoria; euthanasia; homoiousian; improve; interest; is; onto-; Parousia; present (adj.) "existing at the time;" present (n.2) "what is offered or given as a gift;" proud; quintessence; represent; satyagraha; sin; sooth; soothe; suttee; swastika; yes.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit asmi, Hittite eimi, Greek esti-, Latin est, Old Church Slavonic jesmi, Lithuanian esmi, Gothic imi, Old English eom, German ist.

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fylfot (n.)
supposedly a native name for the swastika (used as a decorative device), but only attested in a single, damaged c. 1500 manuscript, and in that it might rather refer to any sort of device used to fill the bottom (foot) of a design. "[I]t is even possible that it may have been a mere nonce-word" [OED].
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