1726, from L. velaris,
"sail, curtain" (see veil
). Originally an architect's term for a type of cupola; phonetics sense is from 1876, on notion of "pertaining to the velum
," the anatomist's name for the soft palate (velum
in this sense is attested from 1771, in full velum palati
). The noun meaning "a velar guttural" is recorded from 1886.