Common words:
* Audacious: Bold, daring, fearless
* Capacious: Spacious, roomy
* Gregarious: Sociable, outgoing
* Loquacious: Talkative, chatty
* Spacious: Roomy, large
* Veracious: Truthful, accurate
Less common, but still valid words:
* Acrimonious: Bitter, sharp, caustic
* Arduous: Difficult, strenuous
* Clamacious: Noisy, clamorous
* Contumacious: Rebellious, defiant
* Efficacious: Effective, successful
* Facetious: Humorous, playful
* Ferocious: Fierce, savage
* Fugacious: Fleeting, transient
* Gracious: Courteous, kind
* Iniquitous: Wicked, unjust
* Meretricious: Flashy, tawdry
* Pernicious: Harmful, deadly
* Sagacious: Wise, discerning
* Tenacious: Persistent, determined
* Voracious: Eager, insatiable
Note: The suffix "-acious" usually indicates a quality or characteristic, often a positive one (e.g., audacious, gracious, capacious), but it can also be used for negative qualities (e.g., acrimonious, pernicious, contumacious).