Fortieth \For"ti*eth\, a. [AS. fe['o]wertigo?a. See Forty.]

1. Following the thirty-ninth, or preceded by thirty-nine units, things, or parts. [1913 Webster]

2. Constituting one of forty equal parts into which anything is divided. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

Fortieth \For"ti*eth\, n. One of forty equal parts into which one whole is divided; the quotient of a unit divided by forty; one next in order after the thirty-ninth. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

fortieth adj : the ordinal number of forty in counting order [syn: 40th]

noun

position 40 in a countable series of things

Source: WordNet (r) 2.0
 

Fortieth \For"ti*eth\, a. [AS. fe['o]wertigo?a. See Forty.]

1. Following the thirty-ninth, or preceded by thirty-nine units, things, or parts.

2. Constituting one of forty equal parts into which anything is divided.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Fortieth \For"ti*eth\, n. One of forty equal parts into which one whole is divided; the quotient of a unit divided by forty; one next in order after the thirty-ninth.

Source: Webster's Revised Unabridged Dictionary (1913)