'Thunderhead' definitions:
Definition of 'thunderhead'
From: WordNet
noun
A rounded projecting mass of a cumulus cloud with shining edges; often appears before a thunderstorm
Definition of 'Thunderhead'
From: GCIDE
- Thunderhead \Thun"der*head`\, n. A rounded mass of cloud, with shining white edges; a cumulus, -- often appearing before a thunderstorm. [1913 Webster]