1. The atmosphere we breathe: Air is composed primarily of oxygen, nitrogen, carbon dioxide, and water vapor.
2. Biosphere, stratosphere, sky: The rocket blasted off into the air.
3. Wind, breeze, draft, current: When Andrea Gill opened the window, cold air blew in through the open window.

To place something in an open area where there is a breeze to make it cool, dry, or clean: Leon's mother taught her children to put the blankets out on the line to air out.

Prior to; before in time: Douglas and Karin will have a warm fire ere nightfall and so ere long they will be comfortable.

1. To make a mistake, slip up, miscalculate: Banks rarely err in figuring a checking account balance.
2. To deviate from an established moral code; to transgress, sin, misbehave: To err is human, to forgive divine.

1. Someone who is legally entitled to inherit and to own an estate after the previous owner’s death; a beneficiary, an inheritor: The millionaire’s only heir was his son, Myron.
2. A person who succeeds or is in line to succeed to a hereditary rank, title, or office: The king did not have an heir when he died.