"pertaining to or of the nature of a cyclone," 1849, from cyclone + -ic. Cyclonal is from 1855.
Entries linking to cyclonic
cyclone n.
1848, "extensive storm characterized by the revolution of air around a calm center in which the wind blows spirally around the center," coined by British East India Company official Henry Piddington to describe the devastating storm of December 1789 in Coringa, India; irregularly formed from a Latinized form of Greek kyklon "moving in a circle, whirling around," present participle of kykloun "move in a circle, whirl," from kyklos "circle" (from PIE root *kwel- (1) "revolve, move round"). Applied to tornadoes from 1856.
-ic
Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).
In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.