This part of the implement is known as Mantha or “the churner.”
She wears seven rings on one hand and four on another, and rustles so when she walks she sounds like a churner out of order.
Old English cyrin, from Proto-Germanic *kernjon (cf. Old Norse kirna, Swedish kärna, Danish kjerne, Dutch karn, Middle High German kern); probably akin to cyrnel "kernel" (see kernel) and describing the "grainy" appearance of churned cream.
mid-15c., chyrnen, from churn (n.). Extended senses are from late 17c. Intransitive sense is from 1735. Related: Churned; churning. To churn out, of writing, is from 1902.
To artificially increase the level of activity in a law firm, insurance company, or other enterprise in order to increase commissions, feign busyness, etc: Policyholders have launched class-action suits alleging churning (1940s+)