"pertaining to or indicated by a barometer," 1780, from barometer + -ic. The older word is barometrical (1660s).
Entries linking to barometric
barometer n.
"instrument for measuring the weight or pressure of the atmosphere," 1660s, from Greek baros "weight" (from suffixed form of PIE root *gwere- (1) "heavy") + -meter. The name probably was coined (and certainly popularized) by English scientist Robert Boyle (1627-1691). The instrument was invented 1643 by Italian physicist Evangelista Torricelli and was at first known as the Torricelli tube.
-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.