Definition of "breather"

Something or someone that breathes.  examples

(specifically) A heavy breather.  quotations  examples

A short break; a rest or respite.  examples

(physics) A spatially localized, time-periodic excitation in a one-dimensional lattice.  examples

(colloquial, dated) That which puts one out of breath, such as violent exercise.  examples

(mechanics) An air inlet path to the crankcase  examples