a machine that simulates an environment for the purpose of training or research
"The flight simulator allowed the trainees to practice emergency landings in various weather conditions without risking real aircraft."
One who simulates or feigns.
"The actor was accused of being a simulator when he faked his own injury to avoid military service."
In plain English: A simulator is a machine that lets you practice doing something real, like flying an airplane, without actually being there.
"The flight simulator helped train new pilots to handle emergency situations safely."
The word simulator comes from the Latin verb simulare, meaning to pretend or imitate, combined with the suffix -or which indicates a person or thing that performs an action. It entered English in the mid-19th century as a device for practicing or simulating specific conditions without actually experiencing them.