O·sage 
(ōsāj′, ō-sāj)
(ōsāj′, ō-sāj)n. pl. Osage or O·sag·es
1. A member of a Native American people formerly inhabiting western Missouri and later southeast Kansas, with a present-day population in north-central Oklahoma. Substantial oil reserves were discovered on Osage lands in the early 1900s.
2. The Siouan language of the Osage.
[French, from Osage wazházhe, ethnic self-designation.]
Osage′ adj.