expiratory

The word expiratory is built upon the Latin verb spirare, meaning "to breathe". This root is combined with the prefix ex-, meaning "out", to form the core concept of "breathing out". The suffix -atory is then added to transform the verbal action into an adjective describing anything pertaining to that act of exhalation. Thus, the literal morphemic construction "out-breathe-relating to" directly and logically yields the modern medical and physiological term for the phase of respiration where air is expelled from the lungs.

Structure: ex (out) + spir (breathe) + atory (adjective suffix) - ex: Latin prefix meaning "out of, from". - spir: Latin root from spirare, meaning "to breathe". - atory: English adjective-forming suffix from Latin -atorius, indicating a relation to an action.