Synonyms for Breather (same or very similar meaning)
WordNet sense 1 (a short respite):
breath, breathing space, breathing place, breathing spell, breathing timeWordNet sense 2 (air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time):
snorkel, schnorchel, schnorkel, snorkel breatherFrom the ODE community, based on WordNetadd/edit