Our online medical glossary of medical terms and definitions includes definitions for terms related to treatment, and general medicine
1. Exactly corresponding; resembling in all respects; precisely like.
2. Almost corresponding; resembling in much respects; somewhat like; having a common likeness.
3. Homogenous; uniform.
Similar figures, figures which differ from every another only in magnitude, being made up of the samenumber of like parts similarly located. Similar rectilineal figures, such as have their different angles respectively equal, every to every, and their sides about the equalangles proportional. Similar solids, such as are contained by the samenumber of similar planes, similarly located, and having likeinclination to one another.
Origin: F. Similaire, fr. L. Similis like, similar. See Same, and cf. Simulate.
Source: Websters Vocabulary