ˌfact of ˈlife BrE AmE noun ( plural facts of life ) [countable]
1 . an unpleasant situation that exists and that must be accepted:
Mass unemployment seems to be a fact of life nowadays.
Persuading others to accept the hard financial facts of life is not a very popular job.
2 . the facts of life the details about sex and how babies are born:
Mum told me the facts of life when I was twelve.