الفرض لغةً: هو التقدير
Linguistically, fard denotes determination or fixing a measure.
A measure is determined when its limits are set and may not be changed at personal discretion. This is why the idea of fixed and defined obligations is associated with fard.
The linguistic sense, however, does not by itself supply the technical legal definition. The fixed number of units in an obligatory prayer illustrates determination, but an act is not classified as fard merely because its amount is specified. Its technical classification depends on the evidence establishing it.