# Definition:Ring Endomorphism

## Definition

Let $\struct {R, +, \circ}$ be a ring.

Let $\phi: R \to R$ be a (ring) homomorphism from $R$ to itself.

Then $\phi$ is a ring endomorphism.

## Also see

• Results about ring endomorphisms can be found here.

## Linguistic Note

The word endomorphism derives from the Greek morphe (μορφή) meaning form or structure, with the prefix endo- (from ἔνδον') meaning inner or internal.

Thus endomorphism means internal structure.