frothy

1 covered with, consisting of, or resembling foam a frothy dessert made of whipped egg whites and fruit puree Synonyms foamy, lathery, sudsyRelated Words bubbly, effervescent, fizzy, sparkling; soapy

2 lacking in seriousness or maturity a frothy comedy that wouldn't exert the brain of a gnat Synonyms birdbrained, ditzy (or ditsy), dizzy, featherbrained, flighty, frivolous, giddy, futile, goofy, harebrained, light-headed, light-minded, puerile, scatterbrained, silly, yeastyRelated Words fatuous, foolish, inane, nonsensical, thoughtless, witless; crazy, daffy, daft, fruity; exuberant, flippant, fluttery, giggly, happy, light, lighthearted, playful; sappy, shallow, superficialNear Antonyms grave, melancholy, somber (or sombre), thoughtful; dignified, heavy, no-nonsense, sedate, severe, solemn, staidAntonyms earnest, serious, serious-minded, sober, unfrivolous

3 being of a material lacking in sturdiness or substance the sort of frothy costumes worn by Las Vegas showgirls Synonyms cobwebby, filmy, flimsy, gauzy, gossamer, gossamery, insubstantial, sleazy, unsubstantialRelated Words dainty, delicate, fine; feeble, fragile, frail; diaphanous, sheer, transparentNear Antonyms durable, knockabout, lasting, tough; coarse, heavy, rough, rudeAntonyms sturdy, substantial