In Lakota the word 'Maske', pronounced Mash KAY, is a term which women use for special friends only.
Lakota is a Siouan language, related to other languages like Dakota and Assiniboine. The Siouan languages are spoken in the USA and Canada by a total of some 23,000 people. There is considerable mutual intelligibility between the Lakota and Dakota languages, but relatively limited mutual intellibility between the other Siouan languages.
Lakota (Lakhóta), spoken by about 9,000 people in seven tribes, the Oglala, in the US states of Northern Nebraska, southern Minnesota, North and South Dakota and northeastern Montana, and also in Canada.
The name "Sioux" is a French version of the Ojibwa word nadewisou, which means "treacherous snakes". The native names for the Sioux mean "An Alliance of Friends", which is Dakhota in the Santee dialect, Nakhota in the Yankton dialect and Lakhota in the Teton dialect. There are a number of different spellings of these names.
See a collection of useful phrases in Lakota Sioux at Omniglot.