vaunt (n.) Look up vaunt at Dictionary.com
"boasting utterance," c. 1400, short for avaunt "a boast" (late 14c.), from avaunten "to boast" (c. 1300), from Old French avanter "boast about, boast of, glory in."
vaunt (v.) Look up vaunt at Dictionary.com
early 15c., "speak vainly or proudly," from Anglo-French vaunter, Old French vanter "to praise, speak highly of," from Medieval Latin vanitare "to boast," frequentative of Latin vanare "to utter empty words," from vanus "empty, void," figuratively "idle, fruitless," from PIE *wano-, suffixed form of root *eue- "to leave, abandon, give out." Also short for avaunten "to boast" (see vaunt (n.)). Related: Vaunted; vaunting.