A compound measure is made up of two (or more) other measures.
Speed is a compound measure made up, in this case, from a
measure of length (kilometres) and a measure of time (hours).
A measure which contains two or more dimensions; e.g.density
whose dimensions are mass/volume. The compound measure density
is made up, in this case, from a measure of mass (grams) and
a measure of volume (cubic centimetres).