, although usually written with hiragana, can also be written as , and means something like "have an air of...". These can be used as na-adjectives:
> an attitude with an air of boastfulness
> speak with an air of (over-)confidence
> a face with an air of sadness
Some can also be used as nouns, but beware, not all of the ones that can be used as na-adjectives are used as nouns. The nouns are most commonly used with (but other uses also occur).
> {}() immature (no air of matureness)
> () impertinent (lit. no air of cuteness)