Medical Definition of Substance

Substance: 1. Material with particular features.
2. The material that makes up an organ or structure. Also known in medicine as the substantia.

Last Editorial Review: 6/9/2016

Search MedTerms:

Back to MedTerms online medical dictionary A-Z List
Pill Identifier Tool

Need help identifying pills and medications?
Use the pill finder tool on RxList.

Health Solutions From Our Sponsors