In the US “sleet” is the term for a winter precipitation that occurs when snow falls through a layer of warm air and melts into water droplets, then re-freezes into ice pellets as it passes through colder air closer to the ground. In many other areas that were part of the British empire that precipitation is called “ice pellets” and “sleet” instead refers to a mix of snow and rain. In the US that’s called a “wintry mix.”
Yes, around here the difference between freezing rain and sleet is that freezing rain is liquid until it lands and it freezes on contact with a cold surface and sleet is solid as it comes down.