schub

Etymology
From,.

Noun

 * 1)  keratinous segment of certain animals' skin
 * 2) pigmented, chitinous segment of butterfly wings
 * 3) a similarly flaky part of the exterior of plants

Etymology
From.

Noun

 * 1)  relapse, flare-up a phase when a person with multiple sclerosis becomes ill again after a period of improvement