Obo-Manobo, one of the tribes in Mindanao Philippines, inhabiting some municipalities in the Province of North Cotabato, has ethnic or indigenous language which is not sufficiently analyzed and documented. To account varieties in language and to come up with the glossary of terms, the researcher used the Metalinguistic knowledge from the interviews, focus group discussions, observations and translation of the Swadesh Word List and from the lexical databases such as the word lists of Obo-Manobo accounted by the SIL. The study revealed distinct variations in the Obo-Manobo language from the culture bearers of Kidapawan City, Magpet and President Roxas in the Province of North Cotabato. Obo-Manobo has lexical varieties in the way they name and describe things, person, places, events and concepts (noun and adjectives); use the main verb, prepositions and conjunctions. These are all accounted in the glossary of terms – the output of this study.