nLab
cyclic ring

A cyclic ring is a cyclic group $\mathbb{Z}/n\mathbb{Z}$ or $\mathbb{Z}$, equipped with its canonical commutative ring-structure induced from multiplication in the integers.

(hm, bad terminology, need disambiguation with the other meaning of cyclic ring)

For $n$ a prime number this is a prime field.

References

e.g. example 5 in these notes: pdf