Monochromatic literally means single colour. Typical of lasers which by their design generate an essentially single frequency.

No, most lasers emit light at a different frequency than UV.

white light is the full visible like spectrum.

lasers are monochromatic. a single or very narrow frequency or wavelength.

All tunable LASERs are LASERS, however not all LASERS are tunable. In a tunable laser the lasing medium, which is typically a gas, dye or crystal, can be altered to produce slightly different frequencies, thus allowing the laser to be 'tuned' or frequency changed where most LASERS produce a very narrow band of radiation frequencies.

T. Ikegami has written:

'Frequency stabilization of semiconductor laser diodes' -- subject(s): Frequency stability, Semiconductor lasers