aerator \aerator\, Aerator \A"["e]r*a`tor\, n.
1. That which supplies with air or gas; specif.:
(a) An apparatus used for charging mineral waters with gas
and in making soda water.
(b) A fumigator used to bleach grain, destroying fungi and
insects.
[Webster 1913 Suppl.]
2. an apparatus for exposing something to the air (as
sewage).
[WordNet 1.5] Aerenchym