English translation: beef. The word actually translates to “a cow – its meat.” So this is more like two words.
Béégashii is the Navajo word for cow, or cattle. The latter part of the phrase, bitsį’, uses the bi- suffix to mean “he” or “it” along with the word -tsį’, which means meat (atsį’).
Here’s a quick info-bit: the Apache language and the Navajo language share similar words for cow — the Apache word using the “maa” sound in place of the Navajo “béé” sound.