Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.

Definition of Amoeba

Medically reviewed by Min Clinic Staff | Updated: January 2026

Amoeba: Also ameba. A single-celled (protozoan) organism that constantly changes shape. The word "ameba" is from the Greek "amoibe" meaning "change." Ameba can infect the bowels to cause diarrhea and the liver to cause abscess formation.