frivolous Antonyms

serious subconscious salient sacred ruling rememberable reigning regnant ranking quintessential sedate seismic staid solemn sober significant signal shrewd sensible seminal protrusile prominent pivotal pertinent peopled parlous parenchyma paramount overriding over populated predominant premier prognathous principal primary primal pressing prerequisite preponderant prepollent outstanding world-shaking big league superordinate major key climactic bare bones axiological asymptotic