air hole
/ˈɛː həʊl/noun
1A hole or passage to admit air; especially a hole in a layer of ice formed over deep water, providing a breathing-place for aquatic animals or divers.
2 Metallurgy. A cavity in a metal casting, produced by the escape of air through the liquid metal. Now rare.
Origin
Early 17th century; earliest use found in Contract. From air + hole.
- polypifer
- polypiform
- polypill
- polypite
- polyplacophoran
- polyplacophore
- polyplastid
- polyploid
- polyploidise
- polyploidization
- polyploidize
- polyploidized
- polyploidizing
- polyploidogenic
- polyploidy
- polypnea
- polypneic
- polypneustic
- polypnoea
- polypnoeic
- polypod
- polypodiaceous
- polypodium
- polypody
- polypody of the oak