How does 飄 + 然 compound to mean 'floating in the air'? ABC Chinese–English Comprehensive Dictionary (2003). I can't access the &quot;slightly revised through July 2005&quot; ed.

Neither 飄 nor 然 mean 'air'. One can drift or float in water, or mentally in one's mind.
飄's  radical is 風 (wind), and 風 is created by the movent of air
然 is a word particle that indicates &quot;like&quot; (in the manner of)
飄然 = like floating (in the air)