noting any metal, especially alloy steel, that can be hardened from above its transformation point by cooling in air.
a process of hardening high-alloy steels by heating and cooling in a current of air Compare oil hardening
an area in enemy territory or in threatened friendly territory, seized by airborne troops for bringing in supplies and additional troops by airdrop or landing. Slang. a scatterbrained, stupid, or simple-minded person; dolt. Contemporary Examples Sure, the critics never quite cottoned to him; they always insinuated that he was an airhead, a blank. Are We […]
- Air hoist
a pneumatic hoist.
- Air hole
an opening to admit or discharge air. a natural opening in the frozen surface of a river or pond. . Historical Examples At Mill Grove he came near losing his life, on a duck-shooting expedition, by falling through an air hole in the ice. Famous Men of Science Sarah K. Bolton There will be areas […]
- Air horn
a horn activated by compressed air.