from The Century Dictionary and Cyclopedia
- Thundering from on high; high-thundering.
Sorry, no etymologies found.
V.M. as "Mère et Fille de _l'aliltonât_ [ant] plasmateur" into "_altitonant_" ( "loud-thundering"), while _plasmateur_ itself, though perfectly intelligible and legitimate, a favourite with the _rhétoriqueurs_, and borrowed from them even in Middle Scots, is not exactly everybody's word.