A system of Fundamental dimensions is such that every other dimension can be generated from them. Traditionally, the accepted fundamental dimensions are mass, length, time, and electric current, but in principle, the 3 other fundamental dimensions could be used ([thermodynamic temperature]?, [amount of substance]?, [luminous intensity]?).
Velocity, for example, is length divided by time, and so can be generated from the above list of fundamental dimensions.
Physics call velocity a [derived dimension]?.
See also: SI system of units, dimensional analysis