breath·er / ˈbrē[voicedth]ər/ • n. 1. [in sing.] inf. a brief pause for rest: the director is taking a breather from his furious schedule.2. a vent or valve to release pressure or to allow air to move freely around something: [as adj.] a breather pipe. 3. a person or animal that breathes in a particular way, or breathes a particular substance: a heavy breather [in comb.] reptiles are lung-breathers.