the period of life just prior to sexual maturation.
Origin of prepuberty
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
The period of life immediately before puberty, often marked by accelerated physical growth.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.