a musical organization consisting of a group of instrumentalists including string players
"The conductor raised his baton, and the entire orchestra began to play their intricate arrangement for the opening night performance."
seating on the main floor in a theater
"The front row of the orchestra offered us a perfect view of the stage performance."
A large group of musicians who play together on various instruments, usually including some from strings, woodwind, brass and/or percussion; the instruments played by such a group.
"The city's annual festival featured a full orchestra performing Beethoven's Ninth Symphony under the direction of a renowned conductor."
In plain English: An orchestra is a large group of musicians who play many different instruments together to perform music.
"The local orchestra performed a beautiful symphony at the city hall last night."
Usage: Use orchestra to refer to a large ensemble of musicians playing string, woodwind, brass, and percussion instruments simultaneously. It can also denote the collective set of instruments used in such a performance.
The word orchestra comes from the Latin orchestra, which was borrowed from the Ancient Greek word for a dancing area. Its original meaning referred to the space in front of the stage where dancers performed before it came to mean the entire band or seating section in modern English.