speciosity
The state or quality of being specious; speciousness.
uncountable
A specious action, promise, ideology, etc.
countable, rare
Till deep misery, if nothing softer will, have driven you out of your Speciosites into your Sincerities; and you find there either is a Godlike in the world, or else ye are an unintelligible madness;
Where it comes from
From Middle English speciouste (“attractiveness”), from Latin speciōsitās (“beauty”), from speciēs (“appearance”). By surface analysis, speci(ous) + -osity.
Adapted from the Wiktionary entry speciosity (CC BY-SA 4.0).