Nonchalant (6)
'nonchalant' is the definition.
(synonyms)
This is all the clue.
(Other definitions for casual that I've seen before include "Far from formal" , "Informal, not methodical" , "Informal or blase" , "Offhand - informal" , "Careless; unsystematic" .)
(Other definitions for breezy that I've seen before include "Fresh and animated" , "Blowy" , "Pleasantly windy" , "Fresh - jaunty" , "Windy - upbeat" .)
'nonchalant' is the definition.
(airy can mean casual or unconcerned)
This is the entire clue.
(Other definitions for airy that I've seen before include "Old astronomer" , "(Of ideas) speculative" , "Breezy" , "Well ventilated; insubstantial" , "Well ventilated; nonchalant" .)
'nonchalant' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for cool that I've seen before include "Level-headed" , "Modern calmness, brrr!" , "Unemotional or trendy" , "Super!" , "Moderate" .)
'nonchalant' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for blase that I've seen before include "Jaded" , "Unimpressed, offhand" , "Bored with sable" , "Surfeited, bored" , "Showing indifference through overfamiliarity" .)