heavy (adj.)

Old English hefig "heavy, having much weight; important, grave; oppressive; slow, dull," from Proto-Germanic *hafiga "containing something; having weight" (source also of Old Saxon, Old High German hebig, Old Norse hofugr, Middle Dutch hevich, Dutch hevig), from PIE root *kap- "to grasp."

The jazz slang sense of "profound, serious" is from 1937 but would have been comprehensible to an Anglo-Saxon. Heavy industry is recorded from 1932. Heavy metal is attested by 1839 in chemistry; in nautical jargon from at least 1744 in the sense of "large-caliber guns on a ship."

While we undervalue the nicely-balanced weight of broadsides which have lately been brought forward with all the grave precision of Cocker, we are well aware of the decided advantages of heavy metal. [United Services Journal, London, 1830]

As a type of rock music, from 1972.

Most other Germanic languages use as their primary word for this their equivalent of Middle English swere, Old English swær, which is obsolete (see sweer).

mid-13c., "something heavy; heaviness," from heavy (adj.). Theatrical sense of "villain" is 1880, short for heavy villain (1843), heavy leading man (1849) or similar phrases.

A "heavy business man," he who performs such parts as Ferardo in the Wife, the Ghost in Hamlet, and Malec, Edmund, Banquo, Buckingham and the principal villains of the drama, [will command at present] from $15 to $20 [per week]. ["The Amateur, or Guide to the Stage," Philadelphia, 1851]