What is "unit fraction"

n. (context arithmetic English) A fraction whose numerator is 1 and whose denominator is a positive integer; for example, $frac12$ or 1/35.

A unit fraction is a rational number written as a fraction where the numerator is one and the denominator is a positive integer. A unit fraction is therefore the reciprocal of a positive integer, 1/n. Examples are 1/1, 1/2, 1/3, 1/4 ,1/5, etc.