noun

• (usually derogatory, uncountable) The quality of being overly refined in an affected way (often used to describe speech or writing, but also visual art and dress).
  "1902, R. Langton Douglas, A History of Siena, New York: E.P. Dutton, Chapter 18, p. 385, [Italian renaissance painter Neroccio] had the fastidiousness, the preciosity, the love of archaisms, of your true decadent."
• (usually derogatory, countable) An instance of preciosity; something that is overly refined in an affected way.
  "“O Father Master, is it possible! (exclaimed the Beneficiary ready to roll about the floor with laughing) is it possible that such preciosities are printed! […]”"
• (obsolete, uncountable) The quality of being precious (of high value or worth).
  "I must be forc’d to say somewhat of Margarites [i.e. pearls] themselves, and I am affraid I shall rather be struck with the deepest amazement and confusion, than be able to expresse their unspeakable worth and preciosity."
• (obsolete, countable) Something of high value or worth.
  "That which is rare (we know) is with all Nations precious, and what is precious they love to appropriate and transferr upon themselves as near as they can […]. So if there be any thing more costly then another, they will hang it on their Bodies […], such as their Ear-rings and Jewells. But these Barbarians seem to exceed them in the curiositie of their application of these Preciosities, they fully implanting them into their very Flesh, as if they were part of their natural Body."