al·to·stra·tus
noun/ˌæltəʊˈstrɑːtəs/
/æltəʊˈstreɪtəs/
[uncountable, countable] (plural altostrati
(specialist)/ˌæltəʊˈstrɑːtaɪ/, /ˌæltəʊˈstreɪtaɪ/, /ˌæltəʊˈstrɑːtiː/, /ˌæltəʊˈstreɪtiː/
/ˌæltəʊˈstrɑːtaɪ/, /ˌæltəʊˈstreɪtaɪ/, /ˌæltəʊˈstrɑːtiː/, /ˌæltəʊˈstreɪtiː/
)- a layer of flat clouds lying at medium height, or one of the clouds that form this layer
高层云 Word Originlate 19th cent.: from modern Latin alto- (from Latin altus ‘high’) + stratus.