Expedience, Expediency,, n.
1. The quality of being expedient or advantageous; fitness or suitableness to effect a purpose intended; adaptedness to self- interest; desirableness; advantage; advisability; -- sometimes contradistinguished from moral rectitude. Divine wisdom discovers no expediency in vice. Cogan. To determine concerning the expedience of action. Sharp. Much declamation may be heard in the present day against expediency, as if it were not the proper object of a deliberative assembly, and as if it were only pursued by the unprincipled. Whately.
2. Expedition; haste; dispatch. [Obs.] Making hither with all due expedience. Shak.
3. An expedition; enterprise; adventure. [Obs.] Forwarding this dear expedience. Shak.
Shades of meaning
Fernald has no entry of its own for expediency; he lists it under profit, utility.
Where he writes about it:
Expediency has respect to profit or advantage, real or supposed, considered apart from or perhaps in opposition to right, in actions having a moral character. — from profit
Expediency (L. ex, out, and pes, foot; literally, the getting the foot out) refers primarily to escape from or avoidance of some difficulty or trouble; either expediency or utility may be used to signify profit or advantage considered apart from right as the ground of moral obligation, or of actions that have a moral character, expediency denoting immediate advantage on a contracted view, and especially with reference to avoiding danger, difficulty, or loss, while utility may be so broadened as to cover all existence through all time, as in the utilitarian theory of morals. — from utility
Policy is often used in a kindred sense, more positive than expediency but narrower than utility, as in the proverb, "Honesty is the best policy." Compare profit. — from utility