Noun from Middle English chyrne, cherne, kyrne ( > Scots kirn), from Old English ċyrn, ċyrin, ċirin ("churn"), from Proto-Germanic *kirnijǭ; verb from Middle English chyrnen from Old English ċernan, from Proto-Germanic *kirnijaną, of unknown origin.

• (RP) IPA: /tʃɜːn/
• (America) enPR: chûrn, IPA: /t͡ʃɝn/

churn (churns, present participle churning; simple past and past participle churned)

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

   • 1717, Joseph Addison, Metamorphoses:

     Churned in his teeth, the foamy venom rose.

2. (transitive, figuratively) To produce excessive and sometimes undesirable or unproductive activity or motion.
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. (of a customer) To stop using a company's product or service.
5. (informal, travel, aviation) To repeatedly cancel and rebook a reservation in order to refresh ticket time limits or other fare rule restrictions.
6. (US, informal, finance, travel) To continually sign up for new credit cards in order to earn signup bonuses, airline miles, and other benefits.
7. (finance) To carry out wash sales in order to make the market appear more active than it really is.

• French: baratter
• German: durchschütteln, aufwühlen
• Italian: frullare, sbattere, ribollire, spumeggiare
• Portuguese: agitar, bater
• Russian: взбива́ть
• Spanish: batir (butter), agitar (water)

• French: agiter
• German: wusseln, rütteln, wühlen
• Russian: метаться

• French: agiter
• German: durchschütteln, aufwühlen
• Italian: spumeggiare, frullare, ribollire

churn

1. A vessel used for churning, especially for producing butter.

   a butter churn

2. A milk churn container for the transportation of milk.
3. Customer attrition; the phenomenon or rate of customers leaving a company.
4. (telecommunications) The time when a consumer switches his/her service provider.
5. (telecommunications) The mass of people who are ready to switch carriers.
6. Cyclic activity that achieves nothing.
   • 2007, Hari Kunzru, My Revolutions, page 102:

     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.

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

• French: baratte
• German: Rührtrommel, Butterfass, Butterfaß (obsolete spelling), Butterfertiger, Kerne
• Italian: zangola
• Portuguese: batedeira
• Russian: маслобо́йка
• Spanish: mantequera (butter), lechera (milk)

• Russian: отток абонентов