air;  atmosphere;  mood;  situation;  someone with no presence;  someone who doesn't stand out at all
 sky;  the skies;  high-altitude sky;  upper air
 sky;  air;  ether;  firmament;  the heavens
 blank space (in documents);  vacuum;  blank;  void
 daydream;  fantasy;  fancy;  vision
 cave;  hollow;  cavity;  hollow
 emptiness;  hollowness;  vacancy;  inanity;  pointlessness;  meaninglessness
 fictitious;  imaginary;  fanciful;  aerial;  overhead
 hollow;  mid-air;  air;  sky
 to fly through the air;  to hurtle through the air;  to strike at something and miss;  to fan the air
 empty seat;  unoccupied seat;  vacancy;  vacant post
 anti-aircraft;  antiaircraft
 vacant land;  unoccupied ground;  empty lot
 blank column;  blank space
 vacant space;  aperture;  gap;  opening
 racing (an engine);  idling (an engine);  going in circles (esp. argument, discussion, etc.);  spinning one's wheels
 unprecedented;  record-breaking
 empty gun;  gun loaded with blanks;  firing a blank
 empty (e.g. argument);  insubstantial;  hollow;  fruitless
 mid-air breakage or disintegration
 vacant post;  vacancy;  post in name only
 vacant or unoccupied room
 abstract or impracticable theory
 Air Self-Defense Force;  ASDF
 air pressure;  pneumatic pressure
 empty conveyance;  empty taxi;  free taxi;  having spaces available (of a parking lot)
 land, sea, and air;  army, navy and air force
 bad (fictitious) bill;  empty promise
 noncommissioned officer of the Japanese Air Self Defense Forces (Defence)
 form is emptiness;  matter is void;  all is vanity
 emptiness is form;  illusion of the reality of matter
 with bare hands;  with or from nothing
 senior master sergeant (JASDF)
 abstract or impracticable theory
 to come to naught;  to come to nought
 the empty nature of all things
 land and air;  land and air forces
 airman first class (JASDF)
 horizon;  point where the sky meets the earth
 empty name;  false reputation
 the kalpa of nothingness (the final aeon of the universe)
 the kalpa of nothingness (the final aeon of the universe)
 Amoghasiddhi;  Infallible Magic (a dhyani-Buddha)
 complete emptiness (i.e. as a denial of the inherent existence of all things);  nirvana (where this emptiness is realized); (arch.)  quiet and lonely
 (Self Defense Force's Air Force) general (defence);  lieutenant;  major
 airman third class (JASDF)
 groundless rumor or story (rumour)
 Chinese water spinach (Ipomoea aquatica);  ong choy;  kang kong;  water morning glory;  water convolvulus;  swamp cabbage
 Chinese water spinach (Ipomoea aquatica);  ong choy;  kang kong;  water morning glory;  water convolvulus;  swamp cabbage
 international airspace;  international space
 earth, water, fire, wind and void (the five elements)
 earth, water, fire, wind and void (the five elements)
 air transportation;  air transport
 airman third class (JASDF)
 vast;  boundless;  wide and empty;  vague and hazy
 atmospheric vibration;  infrasound (as produced by volcanic activity)
 vacant and unthinking;  something that should be there is not
 airman second class (JASDF)
 fictitious transaction;  paper transaction
 airman second class (JASDF)
 fictitious transaction;  paper transaction
 airborne wind power generation;  kite power generation
 explosion without effect;  wasted bullets
 air writing;  spacial calligraphy (artform)
 superficial velocity;  superficial flow velocity
 information on space availability in a parking lot (car park)
 cavity resonator;  microwave resonance cavity;  rhumbataron
 deserted and lonesome;  quiet and alone;  innocent and nonattached;  All is void