nicety

English

From Middle English nicetee, from Old French niceté (“simpleness, foolishness”), from nice (“simple, foolish”); equivalent to nice +‎ -ty.

nicety (countable and uncountable, plural niceties)

A small detail or distinction.
We met the new captain while we were taking enemy fire and were unable to observe the niceties of formal introductions.
- 1689 (indicated as 1690), [John Locke], chapter 3, in An Essay Concerning Humane Understanding. […], London: […] Eliz[abeth] Holt, for Thomas Basset, […], →OCLC:
  the fineness and niceties of words
Subtlety or precision of use; exactness; preciseness.
- 1899 Feb, Joseph Conrad, “The Heart of Darkness”, in Blackwood's Edinburgh Magazine, page 212:
  Afterwards I took it back when it was borne in upon me startlingly with what extreme nicety he had estimated the time requisite for the ‘affair.’
- 1934, Henry G. Lamond, An Aviary On The Plains, page 210:
  [W]e cannot judge with exact nicety whether the hunter or the hunted has the greater dash of toe.
A rocket-propelled grenade doesn't have the nicety of a sniper round, but you must admit its effectiveness.
Delicacy of character or feeling usually from excessive refinement; fastidiousness
- 1815, Jane Austen, Emma, volume II, chapter 18:
  [I]f you knew how Selina feels with respect to sleeping at an inn, you would not wonder at Mrs. Churchill’s making incredible exertions to avoid it. Selina says it is quite horror to her—and I believe I have caught a little of her nicety.
(obsolete) That which is delicate to the taste.

small detail that is nice or polite but not necessary

subtlety or precision of use