As can be gleaned from the fact that it is usually represented in Zhuyin, ㄎㄧㄤ is a bit of slang used primarily in Taiwan, especially among young people.
ㄎ with ㄧ (or k + i in Pinyin) is not a legitimate combination of sounds for modern Mandarin, so it's not likely to have originated there.
Its primary meaning is hard to pin down, but "goofy" (see for example this Reddit thread but also its use in this blog name), "tipsy", "dazed", "in awe" are all possible interpretations. The images on this AppleDaily post might be helpful.
This Reddit thread suggests that it is not a feature of older Taiwanese people, and probably does not come from the Taiwanese varieties of Minnan (i.e. Hokkien). However, this sound (in a high level tone) does exist in Taiwanese, meaning "to steal or snatch". Dictionaries generally write it as 勍; it is also written as 鏘 by some sources. Whether this could have conceivably been extended to the meanings of this slang term - that is something less well defined.