canvas (n.) Look up canvas at Dictionary.com
"sturdy cloth made from hemp or flax," mid-14c., from Anglo-French canevaz, Old North French canevach, Old French chanevaz, literally "made of hemp, hempen," noun use of Vulgar Latin adjective *cannapaceus "made of hemp," from Latin cannabis, from Greek kannabis "hemp," a Scythian or Thracian word (see cannabis).

Latin adjectives in -aceus sometimes were made in Romanic languages into nouns of augmentative or pejorative force. Especially as a surface for oil paintings from c.1700; hence "an oil painting" (1764).