WordReference Random House Unabridged Dictionary of American English © 2026
fas•tu•ous
(fas′cho̅o̅ əs),USA pronunciation adj.
fas′tu•ous•ly, adv.
- haughty;
arrogant. - showy;
ostentatious.
- Latin fastuōsus, equivalent. to fastu(s) haughtiness, arrogance (compare fastidious) + -ōsus -ous
- 1630–40