prairie - plains

["Alfred W. Tüting"]

That's what I found at Douglas Harper's

prairie - 17c., from Fr. prairie, from O.Fr. praerie, from V.L.
*prataria,from L. pratum "meadow," originally "a hollow." The word
existed in M.E. as prayere, but was lost and reborrowed to describe the
American plains.

Interestingly, the original semantics doesn't seem to be 'grass' but
'hollow (spot)', maybe referring to 'wet/watery land' -> 'vegatation/grass'

plain - 13c., from O.Fr. plain, from L. planus "flat, even, level," from
PIE*pla- "flat." Sense of "smooth" is earliest in Eng., meanings of
"simple, sincere, ordinary" are 14c. Of appearance, as a euphemism for
"ill-favored, ugly" it dates from 1749. Plains of the American Midwest
first so called 1684. L. planum was used for "level ground" but much
more common was campus.

Cf. also Italian: 'piano', Spanish:  'llano' (also used in the southern
U.S.)

As for Dakota, Buechel S.J. has:

blabla'ta - [B.: an upland plain] [R.B.: rolling prairie, hills and levels]
fr. blayA - > bla'ye [R.B.:= a plain]| [R.B.:= level]
iyo'blaye - [B.: a plain extending from, as from a hill]
izo' - [B.: an upland plain that is a peninsula]
makxo'blaye - [B.: a plain]
obla'ye - [B.: a level place, a plaint a valley]R.B.: a plain, a level
place]
oka'blaye - [B.: a level place, a plain], cf. blaska'/flat
akhi'c^ipa - [B.: a flat tableland that lies higher than a creek]

I wonder why the French term 'prairie' wasn't adopted, since the
Natives' relationship with the early French immigrants were comparably
close (maybe due to their intimate contacts as e.g. trappers, with
intermarriages etc. - cf. Native last names like Peltier, Deloria <- Des
Lauriers). Yet, one can imagine that the land they lived on and their
very culture was based on meant too much to them to refer to it by a
foreign term.

Alfred

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