The Collaborative International Dictionary of English v.0.48:
marmot \mar"mot\ (m[aum]r"m[o^]t; 277), n. [It. marmotta,
marmotto, prob. fr. L. mus montanus, or mus montis, lit.,
mountain mouse or rat. See Mountain, and Mouse.]
1. (Zool.) Any rodent of the genus Marmota (formerly
Arctomys) of the subfamily Sciurinae. The common
European marmot (Marmota marmotta) is about the size of
a rabbit, and inhabits the higher regions of the Alps and
Pyrenees. The bobac is another European species. The
common American species (Marmota monax) is the
woodchuck (also called groundhog), but the name marmot
is usually used only for the western variety.
[1913 Webster +PJC]
2. Any one of several species of ground squirrels or gophers
of the genus Spermophilus; also, the prairie dog.
Marmot squirrel (Zool.), a ground squirrel or spermophile.
Prairie marmot. See Prairie dog.