"being, existing, or turning up everywhere," 1800, from ubiquity + -ous. The earlier word was ubiquitary (c. 1600), from Modern Latin ubiquitarius, from ubique (see ubiquity). Related: Ubiquitously; ubiquitousness.
"omnipresence," 1570s, from Modern Latin ubiquitas, from Latin ubique "everywhere," from ubi "where" (see ubi) + que "any, also, and, ever," as a suffix giving universal meaning to the word it is attached to, from PIE root *kwe "and." Originally a Lutheran theological position maintaining the omnipresence of Christ.
word-forming element making adjectives from nouns, meaning "having, full of, having to do with, doing, inclined to," from Old French -ous, -eux, from Latin -osus (compare -ose (1)). In chemistry, "having a lower valence than forms expressed in -ic."