Definition of sideration in US English:

sideration

noun

  • The shrivelling or destruction of a part or tissue of the body; mortification, necrosis. Now rare.

Origin

Late 16th century (in an earlier sense). From (i) Middle French syderation, French sidération necrosis, gangrene, influence on a person's life or mental state attributed to the stars and planets, illness attributed to the influence of the stars and planets.

Pronunciation

sideration

/sʌɪdəˈreɪʃn/