aerator

/ˈɛreɪtər/
noun
  1. A device or tool used to add air or gas to something, such as soil, water, or a liquid.
    • The fish tank aerator keeps the water oxygenated for the fish.
    • He rented a lawn aerator to punch holes in the compacted soil.
    • A wine aerator helps the wine breathe and improves its flavor.