Proto-IE: *gambh-, *ghamb-, *gamb-
Meaning: swelling; cheek, buttock
Other Iranian: NPers gumbad 'convexity', Pashto ɣumba 'bump'
Old Greek: pl. gamphá-i̯, gamph[ē]lá-i̯ f. `Kinnbacken eines Tieres'
Russ. meaning: вырост, желвак, щека, ягодица
References: WP I 567
Comments: Probably two roots -- 'Auswuchs' and 'Steiss, Kinnbacke'.
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