What does the prefix "nimbo-" indicate about a cloud?

The prefix "nimbo-" in relation to clouds is indicative of their ability to produce precipitation. This prefix typically precedes cloud types such as "nimbostratus" or "cumulonimbus," both of which are associated with significant rainfall or storms. The term originates from the Latin word "nimbus," which means rain or cloud, emphasizing the characteristic of these clouds to generate moisture that leads to precipitation.

While other options describe different characteristics of clouds, they do not capture the specific precipitation aspect tied to the "nimbo-" prefix. For instance, "layer cloud" relates to the structure (as in stratus clouds), "high-level cloud" refers to clouds situated at greater altitudes (like cirrus), and "shaped like a heap" pertains to cumulus clouds known for their fluffy appearance. However, only "nimbo-" directly communicates the cloud's precipitation potential, making it the correct choice.