Kaiya is of Hawaiian origin, meaning 'sea'. It's a unisex name but often used more for girls. It gained popularity in the United States in the late 20th century and has since been favored by parents seeking unique yet meaningful names.
"The name Kaiya saw a steady increase from 12 births in 2001 to a peak of 15 in 2002, but then dropped to just 6 in 2005, summing up to a total of 33 babies named Kaiya."