A — 1: κυλίω
(Strong's #2947 — Verb — kulio — koo-lee-o'-o )

in the Active Voice denotes "to roll, roll along;" in the Middle Voice in Mark 9:20 , rendered "wallowed."

B — 1: κυλισμός
(Strong's #2946 — Noun Neuter — kulismos — koo'-lis-mah )

"a rolling, wallowing," akin to A (some texts have kulisma), is used in 2—Peter 2:22 , of the proverbial sow that had been washed.