Skip to Content


Pronunciation: fo'kus, fo'si


  1. The point at which the light rays meet after passing through a convex lens.
  2. The center, or the starting point, of a disease process.

[L. a hearth]

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review date: Sep 19, 2016.