Yabai is a very common and casual Japanese to describe things below or above standard. Although this world shouldn’t be used business situations Yabai is widely used among all ages.
Originally this word is used to describe something dangerous, not good, but these day this is also used in a positive way.
(Spending more than this is bad : We can’t spend any more.)
(I haven’t studied at all so I don’t think today’s exam will be really bad.)
He looks a little unusual / weird…
(This curry is sooo delisious!)
(That comedian is really usual = very funny.)
(That girl is so much cute, isn’t she?)
(I screwed up)
Use yabai and improve your Japanese!