The train conductor waved goodbye to the passengers as the train departed.

Meaning: The person in charge of the train moved his hand back and forth to say goodbye to the people on the train as it left the station.

Choice of Words: Conductor is a noun that refers to the person in charge of a train. Waved is a verb that means to move one's hand or arm back and forth as a greeting or farewell. Departed is a verb that means to leave a place.

Alternative Expressions

Related Expressions