Isn't Freezing precip an icing condition?
HC and ShyTorque, A few years ago the FAA legal chaps wrote a response to the AOPA on this subject and in essence, referred them to the AIM, paragraph 7-1-22 and 23.
Not the clearest prose, but thats probably the best practical approach, because if one wants a complete technical definition, including liquid water content and droplet size, one would be asking for info not available in any met office briefing.
Thanks,
John Dixson