magnitude (of a vector or vector quantity)

for: a vector (or vector quantity)

is: a scalar quantity that describes the 'size' or 'length' of the vector [M2.4, M2.5, P2.1, P2.2, P2.7]

is always: positive. [M2.4, M2.5, P2.1, P2.2, P2.7]

is denoted: by or simply by [M2.4, M2.5, P2.1, P2.2, P2.7]

is defined: by [M2.4, M2.5, P2.1, P2.2, P2.7]