Is a cyclocross bike still a road bike, or is it one of those weird hybrid bikes?

It's basically a road bike with mountain bike tires.

DH1 is right on target. I also have a cyclocross bike. I like to refer to it as a two wheeled sport utility vehicle.

A cyclocross bike is a road bike, with knubby tires for traction, but usually not as wide and lighter weight than those found on a mountain bike. A cyclocross bike is usually light-weight as racers usually end up having to carry them at some point during the race.

A hybrid on the other hand is a cross between a road and mountain bike, designed to be ridden both on the road ways as well as on bike trails, and there's no one specific design for them. Some are more like road bikes, and others, more like mountain bikes.

A cyclocross is like an enduro style bike. It is equally capable on the road or dirt. It has the geomotry of a road bike and wheel size is 700C or 650....like a road bike, but usually the tires are low profile knobbies that are wider than a standard road tire. Can have drop bars, cantilever brakes (typically). Much more of an aggressive/performance oriented bike than a hybrid. Not as good off road as a mountain bike or as good on the road as a roadie...but good at both.

IMHO, what most people think of as a hybrid bike, is generally not a performance oriented bike. A cyclo cross bike is a performance bike.

Most of these answers are right on, one other thing to consider in a cyclocross bike is that they typically have a little more relaxed geometry than a true road bike. The geometry allows you to sit up a little higher than you would on a conventional road bike. This allows better control of the bike in the off road conditions that are prevalent at most cyclocross races.

You could very easily swap the nobby tires on the cyclocross bike and put road slicks on there and go out and keep a very reasonable pace on the road. I've got friends that would put slicks on and ride their cyclocross bikes to cyclocross races to swap out with nobbies when they get there and race on the nobbies.

cyclocross bike is definately a road bike.......
but has the ability to accept slightly wider tires & stronger rims. Riding over curbs allot would bust a regular road bike - but not a cylocross bike.
It also has drop handlebars - and no suspension -
Those 2 things - are most recognizable on a road bike reguardless of the tires.

A cyclocross race (what a cyclocross bike is made for) usually consists of the person carrying their bike over the roughest terrain - so it's not a MTN bike...for sure.

A hybrid - would not have drop handlebars...and could have front suspension.

if you want to ride on the road - get a road bike.
If you want to ride off road get a MTN bike.
If you want to ride both road and off road on same bike - a hybrid could work but won't be optimum at the road part. or a cyclocross bike would be OK but it won't be optimum at off road - like a MTN bike would be.

Oh yea cyclocross bikes can seem kinda expensive - they usually aren't made/priced for the entry level rider.