thun·der·head 
(thŭndər-hĕd′)
(thŭndər-hĕd′)n.
The swollen upper portion of a thundercloud, usually associated with the development of a thunderstorm.
- recommend
- recommendable
- recommendation
- recommendatory
- recommended daily allowance
- recommended dietary allowance
- recommender
- recommit
- recommitment
- recommittal
- recompense
- recompose
- recomposition
- recon
- reconcilability
- reconcilable
- reconcilably
- reconcile
- reconcilement
- reconciler
- reconciliation
- reconciliatory
- recondite
- reconditely
- recondition