غَمَامٌ
1.
Clouds: (S, Msb, K:) or white clouds: (K:) or thin clouds: (Jel in ii. 54:) and
غَمَامَةٌ signifies one thereof: (S, Msb, K:) the former being plural of the latter, as also is غَمَايءِمُ: (K:) [or rather غَمَامٌ is a coll. gen. n., of which غَمَامَةٌ is the n. un.:] they are so called because they veil the sky, or because they veil the light of the sun. (TA.)
2.
[Hence,] حَبُّ الغَمَامِ signifies Hailstones, or hail. (TA.) [See an example in a verse cited in article ان, p. 109.]