I. ˈfȯ(r)d.]ēə̇th, -(r)t], ]iə̇th\ adjective
Etymology: Middle English fourtithe, adjective & noun, from Old English fēowertigotha, from fēowertig forty + -otha, -tha -th — more at forty
1. : being number 40 in a countable series
the fortieth day
— see number table
2. : being one of 40 equal parts into which something is divisible
a fortieth share of the money
II. noun
( -s )
Etymology: Middle English fourtithe
1. : number 40 in a countable series
2. : the quotient of a unit divided by 40 : one of 40 equal parts of something
one fortieth of the total