dub (v.1)

"give a name to," originally "make a knight," from late Old English dubbian "knight by ceremonially striking with a sword" (11c.), a word perhaps borrowed from Old French aduber "equip with arms, adorn" (11c.) which is of uncertain origin, probably Germanic, but there are phonetic difficulties. Meaning "provided with a name" is from 1590s. Related: Dubbed; dubbing.

dub (v.2)

"add or alter sound on film," 1929, shortening of double (v.); so called because it involves making an additional recording of voices and combining it with the soundtrack. The type of re-mixed reggae music was so called from 1974, probably for the same reason. Related: Dubbed; dubbing.

updated on October 12, 2018

Definitions of dub from WordNet
dub (v.)
give a nickname to;
Synonyms: nickname
dub (v.)
provide (movies) with a soundtrack of a foreign language;
dub (v.)
raise (someone) to knighthood;
Synonyms: knight
dub (n.)
the new sounds added by dubbing;
Etymologies are not definitions. From, not affiliated with etymonline.