Middle English mous, from Old English mus "small rodent," also "muscle of the arm" (compare muscle (n.)); from Proto-Germanic *mus (source also of Old Norse, Old Frisian, Middle Dutch, Danish, Swedish mus, Dutch muis, German Maus "mouse"), from PIE *mus-, the old Indo-European name of the mouse, retained in several language families (source also of Sanskrit mus "mouse, rat," Old Persian mush "mouse," Old Church Slavonic mysu, Latin mus, Lithuanian muse "mouse," Greek mys "mouse, muscle").
Plural form mice (Old English mys) shows effects of i-mutation. As a type of something timid or weak, from late 14c. Contrasted with man (n.) from 1620s (nor man nor mouse). Meaning "black eye" (or other discolored lump on the body) is from 1842. Computer sense of "small device moved by the hand over a flat surface to maneuver a cursor or arrow on a display screen" is from 1965, though the word was applied to other things resembling a mouse in shape since 1750, mainly in nautical use.
Parturient montes, nascetur ridiculus mus [Horace]
odoriferous reddish-brown substance secreted by the male musk deer (dried and used in medicinal preparations and as a perfume), late 14c., from Old French musc (13c.) and directly from Medieval Latin muscus, from Late Greek moskhos, from Persian mushk, from Sanskrit muska-s "testicle," from mus "mouse" (so called, presumably, for resemblance; see muscle). The deer gland was thought to resemble a scrotum. German has Moschus, from a Medieval Latin form of the Late Greek word. Spanish has almizcle, from Arabic al misk "the musk," from Persian.
The musk-deer, the small ruminant of central Asia that produces the substance, is so called from 1680s. The name musk was applied to various plants and animals of similar smell, such as the Arctic musk-ox (1744). Musk-melon "the common melon" (1570s) probably originally was an oriental melon with a musky smell, the name transferred by error [OED]. Also compare Muscovy.
1680s, "pertaining to muscles," from Latin musculus (see muscle (n.)) + -ar. Earlier in same sense was musculous (early 15c., from Latin musculosus). Meaning "brawny, strong, having well-developed muscles" is from 1736. Muscular Christianity (1857) is originally in reference to philosophy of Anglican clergyman and novelist Charles Kingsley (1819-1875), who rejected the term. Muscular dystrophy is attested from 1877.
You have used that, to me, painful, if not offensive, term, 'Muscular Christianity.' My dear Sir, I know of no Christianity save one, which is the likeness of Christ, and the same for all men, viz., to be transformed into Christ's likeness, and to consecrate to His service, as far as may be, all the powers of body, soul, and spirit, regenerate and purified in His Spirit. All I wish to do is, to say to the strong and healthy man, even though he be not very learned, or wise, or even delicate-minded--in the aesthetic sense: 'You, too, can serve God with the powers which He has given you. He will call you to account for them, just as much as he will call the parson, or the devout lady.' [letter, Oct. 19, 1858, to a clergyman who in a review had called him a "muscular Christian"]
"edible bivalve mollusk," Middle English muscle, from Old English muscle, musscel, from Late Latin muscula (source of Old French musle, Modern French moule, Middle Dutch mosscele, Dutch mossel, Old High German muscula, German Muschel), from Latin musculus "mussel," literally "little mouse," also "muscle;" like muscle, derived from mus "mouse" on the perceived similarity of size and shape (see mouse (n.)). The modern spelling, distinguishing the word from muscle, is recorded from c. 1600 but was not fully established until 1870s.
"triangular, resembling the Greek letter delta," 1741, in deltoid muscle, the large muscle of the shoulder, which is so called for its shape, from Greek deltoeides "triangular," literally "shaped like the letter delta;" see delta + -oid. As a noun, "deltoid muscle," by 1758 (delts, short for "deltoid muscles," is by 1977). Related: Deltoidal.
