ankylosis

noun

1. (countable, uncountable)The growing together of bones to form a single unit.
2. (countable, uncountable)The stiffening of a joint as the result of such abnormal fusion.
3. (countable, figuratively, uncountable)An onset of stiffness or inflexibility.

   “Yet in using the word democracy, one must plead for a distinction, or, better, a reversion, indicated by the curious anchylosis that, at a certain point in their maturity, usually sets in upon words newly put in use to express some august and large spiritual reality.”