Speculative (5)
'speculative' is the definition.
(I know that speculative can be written as risky)
This is all the clue.
(Other definitions for risky that I've seen before include "Treacherous" , "Perilous" , "taking a chance" , "admitting possibility of unpleasant outcome" , "not playing safe" .)
'speculative' is the definition.
(I know that speculative can be written as notional)
This is the entire clue.
(Other definitions for notional that I've seen before include "Speculative, not based on fact" , "Existing as theory, not existing in reality" , "Theoretic" , "Unreal" , "Hypothetical, imaginary" .)
(Other definitions for airy that I've seen before include "Breezy" , "Flippant" , "Lacking substance" , "Ethereal" , "Well ventilated; nonchalant" .)