This is the 1008th most frequent Russian word.
воздушного
"Воздушного" means "air" or "aerial" in English, relating to air or something airborne.
'воздушного' describes 'шара' (balloon) to indicate its nature as an object floating in air.
Я наблюдал за полётом воздушного шара.
I was watching the flight of a hot air balloon.
'воздушного' describes 'змея' (kite), depicting its quality of being lifted and flown in the air.
Мы наслаждались видом воздушного змея в небе.
We enjoyed the view of the kite in the sky.
'воздушного' characterizes 'круассана' (croissant) to express its light and fluffy texture.