Meaning

verb breathe easily again, as after exertion or anxiety

verb undergo the biomedical and metabolic processes of respiration by taking up oxygen and producing carbon monoxide

verb draw air into, and expel out of, the lungs

originFrom Middle English respiren, borrowed from Old French respirer or Latin respīrō (“to blow back, breathe out”), from re- (“back”) + spīrō (“to breathe, blow”).

Etymology from Wiktionary, CC BY-SA 3.0