supererogatory

(-tĭv)
adj.

1. Performed or observed beyond the required or expected degree.
2. Superfluous; unnecessary: "It was supererogatory for her to gloat" (Mary McCarthy).

(soo-puhr-uh-ROG-uh-tor-ee)

adjective
1. Going beyond the call of duty.
2. Superfluous.

Etymology
From Latin supererogare (to pay over and above), from super- (above) + erogare (to spend), from rogare (to ask). Ultimately from the Indo-European reg- (to move in a straight line, to lead or rule) that is also the source of regime, direct, rectangle, erect, rectum, alert, source, and surge

Usage
"Houses signal they are participating with a jack-o-lantern on the porch or in the window, rendering police signs supererogatory." — Sarah Churchwell; It's a Treat, Not a Trick; The Guardian (London, UK); Oct 29, 2007.

---

adjective

1. Being more than is needed, desired, or appropriate: de trop, excess, extra, spare, superfluous, supernumerary, surplus. See excess/insufficiency/enough.
2. Not required, necessary, or warranted by the circumstances of the case: gratuitous, supererogative, uncalled-for, wanton. See necessary/unnecessary.

Deeds that are not ‘required’ but which go beyond the call of duty, as, for example, acts of exceptional goodness and heroism. The category is interesting, in that many ethical theories fail to recognize it: e.g. for a direct utilitarian, either an action maximizes happiness, in which case it ought to be done, or it does not, in which case it ought not to be done. Protestant theology also rejected the category, since in Catholic theology the moral surplus arising from acts of sainthood was the property of the Church, and hence could be bought and sold.

1) observed or performed to an extent not enjoined or required
2) exceeding what is needed: superfluous