only one line can be drawn through a point parallel to another line

one part in five equal parts

a saying that is widely accepted on its own merits

a quantity of liquor equal to one fifth of a United States gallon

(logic) a proposition that is not susceptible of proof or disproof; its truth is assumed to be self-evident

the musical interval between one note and another five notes away from it

position five in a countable series of things

one part in five equal parts