An Etymological Dictionary of the German Language/Kegel
Kegel (1.), m., ‘cone, nine-pin, sight (of a gun),’ from MidHG. and MidLG. k€gel, m., ‘nine-pin,’ also ‘stick, cudgel, OHG. chęgil, ‘stake, plug,’ allied to MidDu. kegghe, Du. keg, ‘wedge,’ ModHG. and Bav. kag, ‘stump.’ OHG. chęgil, ‘plug,’ may have been Goth. *kagils (from pre-Teut. gagho-), and might be cognate with Gr. γόμφο-ς (φ for gh), ‘plug, wooden nail, wedge,’ with the root syllable nasalised. It cannot be decided whether Lith. żaginýs, ‘stake, post’ (żagaras, ‘dry branch’), is allied to Kegel, or rather to Kufe, ‘cheek of a sledge.’
Kegel (2.), m., ‘bastard’ (retained in ModHG. only in the phrase Kind und Kegel, ‘kith and kin’), from MidHG. kęgel, kękel, ‘illegitimate child,’ Of obscure origin.