Mass. Gen. Laws ch. 18, § 5G
(a) As used in this section, the following words shall have the following meanings unless the context clearly requires otherwise:
''Claimant'', a person who suffers a loss from property damage, accident, illness, injury or otherwise for which monies may be provided by liability insurance, workers' compensation or any other third party.
''Date of the loss'', the date on which the property damage, accident, illness, injury or other incident occurs.
''Third party'', an individual, agency, program, entity or insurer including, but not limited to, the claimant's own insurer, that is or may be liable to pay monies on account of the claimant's loss.