D defs.my
Entry 1 sense Webster, 1913

Thunderhead

· Thun·der·head · IPA /ˈθʌndɚˌhɛd/
01 n. A rounded mass of cloud, with shining white edges; a cumulus, -- often appearing before a thunderstorm.
  1. 1.
    A rounded mass of cloud, with shining white edges; a cumulus, -- often appearing before a thunderstorm.