Yabo (unrefined, gauche) (野暮)
"Yabo"means the unsophisticated condition. Although historically an adjective, the opposite of 'iki,' it is used much broadly than 'iki' in daily life.
Therefore, it is not true that 'it is "iki" because it is not yabo.'
Today's 'iki' and yabo
The meaning of 'iki' is often overinterpreted in the modern period, and it is often used without recognition of its precise meaning, like being abused in fashion magazines, etc. However, the meaning of yabo is, relatively-speaking, commonly understood (even though there are different opinions on its specific connotations).
Both yabo and 'iki' can have the meaning of 'Japanese aesthetic judgment', but both terms can also go beyond this meaning - especially yabo. For example, it can be a topic of daily conversation as to whether a particular fashion is yabo or not regardless of whether or not it is Japanese.
The description of yabo is used for clothes, obsession with money, long and repetitive explanation, etc. Also, an emphasis on practicality (which stops short of functional beauty), together with uncritical faith in and dependence on brand can be considered yabo. Outdated fashion can be seen as yabo if it is not considered retro just yet. Kitsch ('vulgar' in German) has similar aspects in terms of vulgarity, but in the way that its thorough 'peculiarity' transcends everything else it sometimes receives positive aesthetic evaluation. As long as it is not confused with retro or kitsch, something that is yabo never receives positive aesthetic evaluation. Hetauma (poor at a glance but distinct and having charm in truth) and datsuryoku-kei (ennui-style) are also different from yabo.
In case of being long and repetitive, 'kiza' was used in the feelings of Edo period.
From a viewpoint of design
In terms of design, some find it yabo if it is too easy to understand. For example, electronic devices which put emphasis on fashion are sometimes designed with buttons so small so that people can't find them easily. In contrast, some radios and mobile phones are designed with simplicity as a priority - targeted at the elderly, even at the risk of being considered yabo.
Also, today's Japanese have an unconscious notion that 'the Japanese language is yabo.'
It is considered that the tendency to take different cultures as iki has been extended. For example, there is a tendency to use katakana (one of the Japanese writing systems based on syllables, mainly used for writing loan words and the names of persons and geographical places that can't be written in kanji) for the name of cars and other products (the best examples are the titles of foreign movies). For such products, Japanese words are not used even for the button's names but rather European and American ones (though it is not necessary).
Concrete examples of yabo
The act of posting many distracting signs in the scenery with good atmosphere.
A bureaucratic nature that sticks too closely to regulations, which is opposite to 'iki' na hakarai (good flexible arrangement)
Lack of consideration (especially in the involvement by a third person in a relationship between a man and woman)
To the question, 'Oh, are you going out?,' someone might answer, 'Yeah, I'm just going out for a minor business...'
In such cases, it is really yabo if you keep asking 'what kind of minor business are you going out for?'
Too many functions and over-preparation, which is opposite to traveling lightly