nephelo-, nephel-, nepho- neph-

(Greek: cloud, clouds, cloudiness)

A convex mirror having one central and five radial parts; used to estimate cloud coverage at any given time.
nephophobia (s) (noun) (no plural)
An excessive fright of clouds: People who experience this phobia will not look up in the sky at the visible masses of water suspended way up in the sky. This fear may be related to other consternations concerning weather, such as impending rain, thunderstorms, or lightning. Some depressions are seasonally related, and for those whose depression occurs during the more darker and overcast months, such heavy thunderclouds can be particularly threatening.
An instrument for observing and determining the direction and velocity of clouds in motion.