Borean (approx.) : KVPV
Meaning : hole, empty
Afroasiatic : *kahVp- ~ *kVpVḥ- 'hole' 1533; *gub- 'hole, well' 1542
Reference : Definitely more than 1 root. ОСНЯ 1, 232-233. [ND 586 *gobV 'plain' compares SH *g(ʷ)ab- 'earth, field' [1213] with Mong. *gobi; perhaps both < *'empty']; ND 651, 911.