Iki (いき, often written 粋) is a traditional aesthetic ideal of human behavior or volition in Japan, roughly "chic, stylish". The basis of iki is thought to have formed among urbane commoners (Chonin) in Edo in the Tokugawa-era. Iki is sometimes misunderstood as simply "anything Japanese", but it is actually a specific aesthetic ideal, distinct from more ethereal notions of transcendence or poverty. As such, samurai, for example, would typically, as a class, be considered devoid of iki, (see yabo). At the same time, individual warriors are often depicted in contemporary popular imagination as embodying the iki ideals of a clear, stylish manner and blunt, unwavering directness. The term became widespread in modern intellectual circles through the book The Structure of "Iki" (1930) by Kuki Shuzo.
Yabo (野暮) is a Japanese term to describe certain unaesthetic quality. 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.
The word yabo was often used by city dwellers, or Chonin (especially those of Edo). It often refers to samurai and farmers (nomin) from outside of Edo, but could also be applied to another chonin. The city dwellers of Edo sometimes called themselves Edokko (similar to New Yorker or Parisian). Proud of having been born and raised in Edo, they had a tendency to despise outsiders. However, the origins of many chonin could be traced back to other areas and backgrounds.
The meaning of the term has expanded and generalized through the modernization of Japan. Today, the word yabo is used more frequently than iki.