to look after a person or animal until they are fully grown [= raise]:
It's a good place to rear young children.
The birds have been successfully reared in captivity.
2 also rear up [intransitive]
if an animal rears, it rises up to stand on its back legs [↪ buck]:
The horse reared and threw me off.
3 also rear up [intransitive]
if something rears up, it appears in front of you and often seems to be leaning over you in a threatening way:
A large rock, almost 200 feet high, reared up in front of them.
to be given a particular kind of food, books, entertainment etc regularly while you are a child:
children reared on TV and video games
if a problem or difficult situation rears its ugly head, it appears and is impossible to ignore:
The problem of drug-taking in sport has reared its ugly head again.