As used in sections 379.121 to 379.125, the following words and terms shall mean:
(1) "Adverse underwriting decision", placement by an insurer or agent of a risk with a residual market mechanism, an unauthorized insurer or an insurer which specializes in substandard risks;
(2) "Insurer", any insurance company, association or exchange authorized to issue policies of automobile insurance in the state of Missouri;
(3) "Policy", an automobile policy providing automobile liability coverage, uninsured motorists coverage, automobile medical payments coverage or automobile physical damage coverage insuring a private passenger automobile owned by an individual or partnership.