Respire comes from Latin respirare ('to breathe again, breathe out'), from re- (intensive, 'back') + spirare ('to breathe'). The historical chain includes Latin respirare and Latin spirare. The quoted older senses, "to breathe again, breathe out", "back", and "to breathe", supply the semantic anchors for respire. The formation is best read as compound and borrowed: the word respire carries its older form-history into a compact English lexical shape. In present English it is used as a verb, "to breathe; to take in and expel air". English derivatives include respiration, respirator, and respiratory; related English forms include respiration, respirator, inspire, expire, and perspire. The result is a verb whose etymology preserves both the older form and the later English specialization.