FOR
REAL: Cooper was originally an English surname, denoting someone who made barrels for a living. It's been used for boys since at least the 1880s, though it didn't get popular until the 2000s. It is occasionally used for girls as well. In 2013, it was #93 in the US Top 7000 for boys and #1239 for girls.
diminutives: Coop
other recorded spellings: Kooper, Kuper, Couper, Kouper