having come to an end or become void after passage of a period of time, that is no longer valid, that has been breathed out, verb_ Simple past tense and past participle of expire

The act of breathing out; exhalation, The act of coming to a close; termination, That which is expired; matter breathed forth; that which is produced by breathing out, as a sound

exponent, exponential, noun_ An abbreviation of ex parte, mathematics exponential function, of expired