Yabo is the antonym of iki. Busui (無粋), literally "non-iki," is synonymous with yabo. A non-iki thing is not necessarily yabo but probably is. Something that is yabo is usually unrefined, gigantic, coarse, childish, colorful, self-conscious, permanent, loud, superficial, vulgar, snobbish, boorish, etc.
https://www.youtube.com/watch?v=GD6qtc2_AQA