fact of life: Meaning and Definition of

fact' of life'

Pronunciation: [key]
  1. any aspect of human existence that must be acknowledged or regarded as unalterable: Old age is a fact of life.
  2. the facts concerning sex, reproduction, and birth: to teach children the facts of life.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.