What is the plural of the English word 'mouse'?

The plural of the English word “mouse” is mice.

This is an irregular, or mutated, plural: the vowel sound changes instead of the noun simply taking the usual -s ending. The same kind of historical vowel change appears in pairs such as foot and feet, tooth and teeth, and goose and geese. These forms descend from older Germanic patterns in which a following sound influenced the vowel of the preceding syllable.

“Mice” is the standard modern plural for the small rodent. “Mouses” is not the normal plural of the animal, although it is an accepted variant in some technical contexts for computer pointing devices. That distinction can cause confusion: dictionaries and technology writing may use either “computer mice” or “computer mouses,” with “mice” more common.

The word mouse can refer to many small rodents, not only species in the genus Mus. The best-known species is the house mouse, Mus musculus. In computing, the device received its name partly because its shape and cord suggested a small animal; Douglas Engelbart publicly demonstrated a mouse-controlled computer system in 1968.