What is Concomitant?

Concomitant definition and meaning on Health terms:
Something that exists or occurs at the same time as something else. It can be a natural event, but in medicine is used when referring to: Concomitant medication: two or more medicines are given at the same time when treating diseases, or Concomitant disease: a second disease (or more) is present at the same time as the primary disease (or secondary symptoms occur with a main symptom).