Freeboard means a factor of safety usually expressed in feet above a flood level for purposes of floodplain management. "Freeboard" tends to compensate for the many unknown factors that could contribute to flood heights greater than the height calculated for a selected size flood and floodway conditions, such as wave action, blockage of bridge or culvert openings, and the hydrological effect of urbanization of the watershed.
Opaque means impenetrable to sight.
Seaplane means a fixed wing aircraft which is designed for taking off and landing on water and includes amphibians operated as seaplanes;
Roomer means a person occupying a dwelling unit that lacks a major bathroom or kitchen facility, in a structure where one or more major facilities are used in common by occupants of the dwelling unit and other dwelling units. Major facility in the case of a bathroom means toilet, or either a bath or shower, and in the case of a kitchen means refrigerator, stove or sink.
Tunnelling means the construction of any tunnel beneath the natural surface of the earth for a purpose other than the searching for or winning of a mineral