Altocumulus

Part of speech: noun

Definitions

1. A type of cloud characterized by a layer of white or gray, often forming in patches that resemble waves or ripples in the sky
2. A cloud formation consisting of rounded masses that may indicate a change in weather, typically occurring in the mid-altitude range
3. Forming at altitudes between 2,000 and 7,000 meters, these clouds often signal fair weather but can also precede precipitation or storms

Etymology: Altocumulus is a compound of two Latin words: "altus", meaning "high", and "cumulus", meaning "heap" or "pile". The cloud's name therefore describes its shape and position at once, a heap of cloud sitting higher than the cumulus clouds that bulk up near the ground. The "alto-" element is the same one found in words like "altitude", which shares its root and tells you that height is the idea built into the name. Because "altus" once also meant "deep" as well as "high", the Latin prefix carries a faint double sense that English speakers rarely notice today. In the cloud's case, though, only the height is relevant: the name was built to separate the middle layer from the lower cumulus and the upper cirrocumulus, marking a position in the sky rather than a particular look.