Definition of alastrim in English:

alastrim

Pronunciation /əˈlastrɪm/

noun

Medicine
  • A mild form of smallpox with a low mortality rate, caused by a variola virus of reduced virulence.

Origin

Early 20th century; earliest use found in The Lancet. From Brazilian Portuguese alastrim from alastrar to spread, disseminate, to sprinkle, to cover or steady with ballast + -im, suffix.