muscular (adj.)
1680s, "pertaining to muscles," from Latin musculus (see muscle (n.)) + -ar. Earlier in same sense was musculous (early 15c.). Meaning "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). Muscular dystrophy attested from 1886.