Amongst other effects he had a surpassing notion for the storm. Kean has seen a mechanical exhibition in Spring Gardens (the remains of Loutherburg's “Eidophusicon”) in which very striking procellous effects has been produced, and which he fancied very available to his purpose.
-- George Raymond, Memoirs of Robert William Elliston: Comedian
The plan traced on our chart will lead us through oceans procellous and perilous straits, amid regions where the atmosphere is cheerless and the sun's rays are pale, and the spring blossoms no sooner unfold their petals than they droop and languish.
-- C.C.C.P. Silva, M.D., The Western Medical Reporter, Vol. 10
Procellous is derived from the Latin word procella meaning “storm” and the suffix -ous which implies a general sense, like in the word operose.