A 'ROMpler' is a musical device that uses audio samples instead of oscillators for sound generation, with the sample waveforms stored in ROM (as opposed to RAM or equivalent). A ROMpler cannot sample audio to create new sounds, unlike a conventional 'Sampler'. The audio samples in a ROMpler are pre-loaded by the manufacturer. Most Romplers allow the mixing of different samples in layers, and to change the filters and envelopes, add effects etc. One advantage of a rompler is that there is no need to setup keymapping etc as that is all taken care of by the manufacturer.
The Roland JV1080 is a classic example of a ROMpler.
However, there is something of a grey area between Sampler and ROMpler since some instruments have no user-sampling capability yet new audio waveforms can be loaded by the user into the memory via a computer interface. The Yamaha SY85 is an old example of this kind of setup, while the Kurzweil K2700 is a more modern example.