Does "nose dive" have a technical aviation meaning?
Are there types of dives which do not involve a nose-down attitude?


Yes (although these are not always intentional): a graveyard spiral can occur without a nose down attitude. You can also stall a plane nose high and begin diving to the ground maintaining a stalled nose high attitude, this is similar to what happened to AirFrance 447. A flat spin will also result in "falling" vertically with a relatively flat nose attitude.

In my experience "nose dive" and "dive" are generally interchangeable.