Meaning of achievement age

achieve'ment age"

Pronunciation: [key]
— Psychol. Psychol.
  1. the level of educational development of an individual as determined by an achievement test and based on a comparison of the examinee's score with the average score of individuals of the same chronological age. Cf. mental age.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.