au

audacious (adj.) excessively bold (The security guard was shocked by the fan’s audacious attempt to offer him a bribe.)

audible (adj.) able to be heard (The missing person’s shouts were unfortunately not audible.)

augment (v.) to add to, expand (The eager student seeks to augment his knowledge of French vocabulary by reading French literature.)

auspicious (adj.) favorable, indicative of good things (The tennis player considered the sunny forecast an auspicious sign that she would win her match.)

austere (adj.) very bare, bleak (The austere furniture inside the abandoned house made the place feel haunted.)