copious:  Copious comes, either directly or via Old French copieux, from Latin copiōsus, a derivative of copia ‘abundance’ (from which English also gets copy). Copia itself was originally a compound noun, formed from the intensive prefix com- and ops ‘wealth, power’. => copy, opulent
mid-14c., from Latin copiosus "plentiful," from copia "an abundance, ample supply, profusion, plenty," from com- "with" (see com-) + ops (genitive opis) "power, wealth, resources," from PIE root *op- (1) "to work, produce in abundance," (see opus). Related: Copiously.