Aeration

7 clues
Exposure to air
Ventilator's job
Soda-making process
Carbon dioxide treatment
Lawn improvement process
Function of a faucet insert
Treatment with carbon dioxide
Similar answers:
Abbreviation
Abbreviations
Abducktion
Abduction
Aberration
Aberrations
Abjuration
Ablation
Ablution
Abolition
Abolitions
Abomination
Abortion
Abovementioned
Abridgeddiction
Absenceofmotion
Absolution
Absorption
Abstentions
Abstraction