someone who works on a telephone switchboard, who you can call for help:
Hello, operator? Could you put me through to Room 31?
someone who operates a machine or piece of equipment
computers which can be used by untrained operators
a person or company that operates a particular business:
new regulations affecting taxi operators
Julian travelled with Caribbean Connection, the UK 's leading Caribbean tour operator (=company that arranges holidays).
a private operator running regular passenger services
someone who is good at achieving things by persuading people to help or agree with them:
Monsieur Valentin was a formidable political operator.
He may not look it, but Newman is a smooth operator (=someone who is good at persuading people but who you feel you cannot trust).