Merriam-Webster Collegiate Dictionary - maturation

 noun  Date: 1541  1.  a. the process of becoming mature  b. the emergence of personal and behavioral characteristics through growth processes  c. the final stages of differentiation of cells, tissues, or organs  2.  a. the entire process by which diploid gamete-producing cells are transformed into haploid gametes that includes both meiosis and physiological and structural changes  b. spermiogenesis  • ~al adjective