air*
Here are some words that match your criteria:

- air
- air alert
- air attache
- air attack
- air bag
- air base
- air bladder
- air bubble
- air castle
- air cell
- air cleaner
- Air Combat Command
- air compressor
- air conditioner
- air conditioning
- Air Corps
- air cover
- air crew
- air current
- air cushion
- air defense
- air division
- air duct
- air embolism
- air filter
- air flow
- air force
- air force academy
- Air Force Intelligence Surveillance and Reconnaissance
- Air Force ISR
- air force officer
- Air Force Research Laboratory
- Air Force Space Command
- air gas
- air group
- air gun
- air hammer
- air hole
- air horn
- air hose
- air hostess
- air jacket
- air lane
- air letter
- air lock
- air mail
- air marshal
- air mass
- air mattress
- Air Medal
- air mile
- Air National Guard
- air out
- air passage
- air plant
- air pocket
- air pollution
- air potato
- air power
- air pressure
- air pump
- air raid
- air reconnaissance
- air rifle
- air sac
- air search radar
- air shaft
- air sick
- air sickness
- air sleeve
- air sock
- air space
- air spring
- air station
- air terminal
- air thermometer
- air traffic
- air transport
- air transportation
- air transportation system
- air travel
- air traveler
- air traveller
- air unit
- air wave
- air well
- air-breathing
- air-condition
- air-conditioned
- air-cooled
- air-dried
- air-drop
- air-dry
- air-filled
- air-intake
- air-raid shelter
- air-slake
- air-tight
- air-to-air
- air-to-air missile