As used in this chapter, the following words shall have the following meanings:—
''Commissioner,'' the commissioner of public health.
''Department,'' the department of public health in the Executive Office of Health and Human Services.
''Marijuana,'' the plant Cannabis sativa L., tetrahydrocannabinol, or a chemical derivative or synthesis of tetrahydrocannabinol.
''Physician,'' a person licensed in accordance with the provisions of section two of chapter one hundred and twelve.