or culture pearl
a pearl induced to form by placement of a grain of sand or another irritating object within the shell of a pearl oyster or mussel.
Origin of cultured pearl
First recorded in 1920–25
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a pearl induced to grow in the shell of an oyster or clam, by the insertion of a small object around which layers of nacre are deposited
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012