Based on the provided reference ("What is Clipping in DJing? - YouTube"), a "clip DJ" is likely a DJ experiencing clipping, an audio distortion that occurs when the audio signal exceeds the maximum level that the equipment can handle. The reference shows that this can be visually identified on a DJ mixer.
Clipping, in the context of DJing, refers to the distortion created when the audio signal's amplitude goes beyond the maximum level the audio equipment can accurately reproduce. This results in a harsh, unpleasant sound. You can usually see it on the DJ mixer.
