1590s, "of good omen" (implied in auspiciously), from Latin auspicium "divination by observing the flight of birds," from auspex (genitive auspicis) + -ous. Related: Auspiciousness.
Entries linking to auspicious
auspex n.
"one who observes flights of birds for the purpose of taking omens," 1590s, from Latin auspex "interpreter of omens given by birds," from PIE *awi-spek- "observer of birds," from root *awi- "bird" + root *spek- "to observe." Compare Greek oionos "bird of prey," also "bird of omen, omen," and ornis "bird," which also could mean "omen."
-ous
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."