Stories We Like: Novels For Language Lovers
1640s, "course, direction," from Latin ductus "a leading," past participle of ducere "to lead" (see duke (n.)). Anatomical sense is from 1660s. Meaning "conduit, channel" is 1713; that of "air tube in a structure" is from 1884.
A tubular bodily canal or passage, especially one for carrying a glandular secretion such as bile.