A mongoose is a small terrestrial carnivorous mammal belonging to the family Herpestidae. This family is currently split into two subfamilies, the Herpestinae and the Mungotinae.

The English word "mongoose" used to be spelled "mungoose" in the 18th and 19th centuries. The name is derived from names used in India for Herpestes species: muṅgūs or maṅgūs in classical Hindi; muṅgūs in Marathi; mungisa in Telugu; mungi, mungisi and munguli in Kannada.

The form of the English name (since 1698) was altered to its "-goose" ending by folk etymology. The plural form is "mongooses".

Mongooses have long faces and bodies, small, rounded ears, short legs, and long, tapering tails. Most are brindled or grizzly; a few have strongly marked coats which bear a striking resemblance to mustelids. Their nonretractile claws are used primarily for digging. Mongooses, much like goats, have narrow, ovular pupils. Most species have a large anal scent gland, used for territorial marking and signaling reproductive status.

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