k8s is derivative of kubernetes, where number 8 stands for 8 letters between k and s.

^K[a-zA-Z]{8}s$

but what k3s stands for? It meant to be smaller k8s. But word behind of this is unknown. Here are the options.

Knobs

Knits

Knots

Kicks

Keeps

Kites

Kings

Kales

Kudos

Kubes