cubic kilometer(n = noun.quantity) cubic kilometre - a unit of capacity equal to the volume of a cube one kilometer on each edge;
is a kind of metric capacity unit
has parts: cubic meter, cubic metre, kiloliter, kilolitre

cubic, cubic centimeter, cubic centimetre, cubic content unit, cubic decimeter, cubic decimetre, cubic foot, cubic inch, cubic kilometre, cubic measure, cubic meter, cubic metre, cubic millimeter, cubic millimetre, cubic yard, kilometer