a small orchestra, commonly of about 25 players.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
British Dictionary definitions for chamber orchestra
a small orchestra consisting of about 25 players, used for the authentic performance of baroque and early classical music as well as modern music written specifically for a small orchestra
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