breather

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. One that breathes, especially in a specified manner: a shallow breather.
2. n. Informal A short rest period: took a breather after skiing for two hours.
3. n. Informal An activity, such as strenuous exercise, that causes difficult breathing.
4. n. A small vent allowing the passage of gas or liquid to or from an enclosed area.

Century Dictionary and Cyclopedia

1. n. One who breathes or lives.
2. n. One who utters or whispers.
3. n. One who animates or inspires.
4. n. Anything, as a walk, gymnastic exercise, etc., that stimulates or gives healthy action to the breathing organs.

Wiktionary

1. n. Something or someone that breathes.
2. n. A short break; a rest or respite.
3. n. physics A spatially localized, time-periodic excitation in a one-dimensional lattice.
4. n. colloquial, dated That which puts one out of breath, such as violent exercise.

GNU Webster's 1913

1. n. One who breathes.
2. n. One who lives.
3. n. One who utters.
4. n. One who animates or inspires.
5. n. colloq. That which puts one out of breath, as violent exercise.
6. n. colloq. a pause to catch one's breath, or for some other form of rest or refreshment; -- often used in the phrase to take a breather, i.e. to pause for refreshment.
7. n. a vent in a container to allow equalization of internal and external pressure.
8. n. an air intake pipe to provide air to machinery or people submerged or otherwise sealed off from the outside.

WordNet 3.0

1. n. air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time
2. n. a short respite