churn

verb

1. (transitive)To agitate rapidly and repetitively, or to stir with a rowing or rocking motion; generally applies to liquids, notably cream.

   “Now the cream is churned to make butter.”

   “no-churn ice cream”

   “Churned in his teeth, the foamy venom rose.”

2. (figuratively, transitive)To produce excessive and sometimes undesirable or unproductive activity or motion.

   “The slope of the terrain, shaped like a funnel, squeezed the growing swell of churning snow into a steep, twisting gorge.”

3. (intransitive)To move rapidly and repetitively with a rocking motion; to tumble, mix or shake.

   “I was so nervous that my stomach was churning.”

4. To stop using a company's product or service.

   “Subscriptions can be ended or canceled, which is known as churn. If there are no subscriptions, a customer churns when they stop using the product.”

5. (informal)To repeatedly cancel and rebook a reservation in order to refresh ticket time limits or other fare rule restrictions.
6. (US, informal)To continually sign up for new credit cards in order to earn signup bonuses, airline miles, and other benefits.
7. To carry out wash sales in order to make the market appear more active than it really is.
8. (Internet)To digest.

noun

1. (countable, uncountable)A vessel used for churning, especially for producing butter.

   “a butter churn”

2. (countable, uncountable)A milk churn (container for the transportation of milk).

   “As the ends of the up and down platforms are not opposite each other, it is not possible to provide the ordinary type of barrow crossing, and the full churns were too heavy to be man-handled up and down the stairs of the footbridge.”

   “In the old days, milk trains consisted entirely of vans loaded with ten-gallon churns. When filled, these churns weigh 130 lb. each and their manipulation is an art. [...] Like the tank wagons, the churns are dairy property, but farmers often have other ideas, and find their own uses for them—it has not been unknown for dairy inspectors to find missing churns tucked away in an unsuspected corner of a farmhouse, filled to the brim with banknotes!”

3. (uncountable)Customer attrition; the phenomenon or rate of customers leaving a company.
4. (countable, uncountable)The time when a consumer switches his/her service provider.
5. (countable, uncountable)The mass of people who are ready to switch carriers.
6. (countable, uncountable)Cyclic activity that achieves nothing.

   “I wished my brain would shut up and knew that soon I'd have to start tidying, but first I needed to rest, so I tried to quell the pointless churn behind my eyes and kept on trying (in a minute) until Vicky came back home.”

   “Getting the right manager has just been made more difficult by not having Champions League to offer. There will also be a huge churn of players after the lavish, unrewarding outlay this season.”

7. (countable, historical, uncountable)The last grain cut at harvest; kern.