For"ti*eth (?), a. [AS. feówertigo&?;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.

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.

• The ordinal form of the number forty.
  
• The person or thing in the fortieth position.
  
• One of forty equal parts of a whole.