As used in this chapter, the following terms shall have the meanings indicated:
A.
board – Means the earth removal board, consisting of one member of the board of selectmen, one member of the planning board, one member of the conservation commission, one member of the board of health and the director of public works. The members of the earth removal board who are drawn from multiple-member bodies shall be designated annually by the body they represent.
B.
earth – Means soil, loam, sand, gravel, stone, rock and other, similar natural materials.