Historically the terms were:

App-o-Rama (AoR) = apply for lots of cards for bonuses or 0% lines (back when savings accounts and CDs paid good rates).

Churn = get the same bonus for the same card after a period of time (e.g. Citi Hilton, US Air, Citi AA after 18-24 months). It varies, but you may not have to cancel a card to churn it.

Lots of folks say churn in place of AoR.

Tactically, don't pre-close a card for an app of a different card from the same issuer. Reports are the banks do not immediately release the credit. Instead, apply, if rejected offer to reallocate or close the line when on the phone with reconsiderations.