French phrase
Un instant, s'il vous plaît.
Meaning
One moment, please.
When to use it
A polite request for a short wait. Common on the phone or in offices, it is courteous and not too formal.
Example dialogue
Bonjour, je voudrais parler au responsable.
Hello, I'd like to speak to the person in charge.
Un instant, s'il vous plaît. Je vous le passe.
One moment, please. I'll put you through.