"a wanderer, one of a tribe of people who have no fixed abode," 1550s (in plural, nomades), from French nomade (16c.), from Latin Nomas (genitive Nomadis) "wandering groups in Arabia," from Greek nomas (genitive nomados, plural nomades) "roaming, roving, wandering" (from place to place to find pasturage for their flocks or herds), related to nomos "pasture, pasturage, grazing," literally "land allotted" (from PIE root *nem- "assign, allot; take").
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.