The answer to 'toilet frozen' is that a frozen toilet is a common problem during the winter months, caused by the water inside the toilet tank and bowl freezing. Symptoms include the toilet not flushing, water not filling the bowl, and possibly water leaks or damage.
The best solution depends on the extent of the freezing. For minor freezing, you may be able to thaw the toilet by pouring warm (not boiling) water into the bowl and tank. For more severe freezing, you may need to use a space heater or heat lamp to gradually warm the area around the toilet. If the pipes leading to the toilet are also frozen, you'll need to thaw those as well. If the freezing has caused damage to the toilet or plumbing, it's best to call a professional plumber to inspect and repair the issue.