The Collaborative International Dictionary
Alto-cumulus
Alto-cumulus \Al`to-cu"mu*lus\, n. [L. altus high + L. & E. cumulus.] (Meteor.) A fleecy cloud formation consisting of large whitish or grayish globular cloudlets with shaded portions, often grouped in flocks or rows.
Usage examples of "alto-cumulus".
Sure enough, when he looked outside, there were high alto-cumulus clouds and a thunderhead building.