χερμάς

The entry by Beekes in his Etymological Dictionary of Greek reads (in paraphrase):

"From Proto-Hellenic *kʰermáts. Connected with χείρ (kheír, “hand”) by ancient sources, this word reminds of χέρμα (khérma, “pebble”) and χέραδος (khérados, “silt, gravel”), which are also unclear. If the word belongs to χέραδος (khérados), it is probably Pre-Greek. Otherwise, it may be from the Proto-Indo-European root *gʰer- along with χέρμα (khérma) and κέγχρος (kénkhros). The formally unobjectionable connection with Proto-Indo-Iranian *ȷ́ʰarmyám (“permanent house, building”) remains hypothetical because of the meaning."

χερμᾰ́ς • (khermás) f (genitive χερμᾰ́δος); third declension

1. large pebble or stone, especially for throwing or slinging, slingstone

   Synonym: σφενδόνη (sphendónē)

2. (in later poets) large block of stone

• “χερμάς”, in Liddell & Scott (1940) A Greek–English Lexicon, Oxford: Clarendon Press
• “χερμάς”, in Liddell & Scott (1889) An Intermediate Greek–English Lexicon, New York: Harper & Brothers
• χερμάς in Bailly, Anatole (1935) Le Grand Bailly: Dictionnaire grec-français, Paris: Hachette
• Beekes, Robert S. P. (2010) “χερμάς”, in Etymological Dictionary of Greek (Leiden Indo-European Etymological Dictionary Series; 10), with the assistance of Lucien van Beek, Leiden, Boston: Brill, →ISBN, page 1626