1.  expiration(n = noun.time) expiry, termination - a coming to an end of a contract period; "the expiry of his driver's license"
is a kind of end, ending
Derived form verb expire₁

2.  expiration(n = noun.event) departure, exit, going, loss, passing, release - euphemistic expressions for death; "thousands mourned his passing"
is a kind of death, decease, expiry
Derived form verb expire₂

3.  expiration(n = noun.act) breathing out, exhalation - the act of expelling air from the lungs; Array
is a kind of breath
is a part of breathing, external respiration, respiration, ventilation
has particulars: huffing, puffing, snorting, blow, puff, wind
Derived form verb expire₃

1.  The act of expiring [1913 Webster]
"The true cause of cold is an expiration from the globe of the earth."
"Before the expiration of thy time." [1913 Webster]

2.  That which is expired; matter breathed forth; that which is produced by breathing out, as a sound. [1913 Webster]
"The aspirate “he,” which is . . . a gentle expiration." [1913 Webster]

expiration, n.
1 breathing out.
2 expiry.

Etymology:
L expiratio (as EXPIRE)

N  end, close, termination, desinence, conclusion, finis, finale, period, term, terminus, endpoint, last, omega, extreme, extremity, gable end, butt end, fag-end, tip, nib, point, tail, verge, tag, peroration, bonne bouche, bottom dollar, tail end, rear guard, consummation, denouement, finish, fate, doom, doomsday, crack of doom, day of Judgment, dies irae, fall of the curtain, goal, destination, limit, determination, expiration, expiry, extinction, extermination, death, end of all things, finality, eschatology, break up, commencement de la fin, last stage, turning point, coup de grace, deathblow, knock-out-blow, sockdolager, ending, final, terminal, definitive, crowning, last, ultimate, hindermost, rear, caudal, vergent, conterminate, conterminous, conterminable, ended, at an end, settled, decided, over, played out, set at rest, conclusive, penultimate, last but one, last but two, unbegun, uncommenced, fresh, finally, in fine, at the last, once for all, as high as Heaven and as deep as hell, deficit omne quod nascitur, en toute chose il faut considerer la fin, finem respice, ultimus Romanorum.