The OP asked a question, without specifics as to what is meant by "single driver" and "fullrange speaker". Seems like most responses discuss a dynamic speaker as a "single driver", and full-range speaker as s comparative well-known or accepted model that reproduces a wide enough audio frequency range to be called "fullrange".
My take on the question is a single radiating surface unit (speaker) that can come closest to reproducing the full range of audio frequencies (20 Hz to 20 kHz). Nowhere in the question is the required levels of distortion, power handling, efficiency, waveform accuracy, dynamic compression, linearity, sound coverage (dispersion), etc.
My take on the question is a single radiating surface unit (speaker) that can come closest to reproducing the full range of audio frequencies (20 Hz to 20 kHz). Nowhere in the question is the required levels of distortion, power handling, efficiency, waveform accuracy, dynamic compression, linearity, sound coverage (dispersion), etc.