上域

上域	shàng yù	(math.) codomain
上	shǎng	used in 上声
上	shàng	(bound form) up; upper; above; previous / first (of multiple parts) / to climb; to get onto; to go up / to attend (class or university) / (directional complement) up / (noun suffix) on; above
域	yù	field / region / area / domain (taxonomy)