altocumulus
noun [ U ] environment specialized uk/ˌæl.təʊˈkjuː.mjə.ləs/ us/ˌæl.toʊˈkjuː.mjə.ləs/
高积云
a type of cumulus (= a tall, rounded, white cloud with a flat base) found at medium height, above the level of cumulus
Compare: cirrocumulusstratocumulus