1. A uniformed attendant or porter employed at the entrance of a building, hotel, or office to assist visitors and perform errands.
Usage: Chiefly British English; Common in formal or institutional settings
2. A person appointed to carry out the duties of a commission or to represent an organization in an official capacity.
Usage: Formal or administrative use

Examples

• The commissionaire at the hotel entrance greeted guests and called taxis for them.
• A uniformed commissionaire stood by the revolving doors of the office building.
• The commissionaire helped the elderly woman carry her packages inside.
• The government appointed a commissionaire to oversee the investigation.
• The commissionaire in the lobby was always helpful and courteous to visitors.