Learner's definition of LEGAL
1 a : of or relating to the law
b : based on the law
She has a lot of legal problems.
a legal adviser/representative
a country's legal system [=the way that laws are made and controlled in a country]
Do you know your legal rights?
The amount of alcohol in his blood exceeded the legal limit.
He plans on taking legal action against the company. [=he plans on having a court of law settle his argument with the company]
legal proceedings [=actions taken to settle an argument in a court of law]
2 : allowed by the law or by the rules in a game
What you did was not legal.
“Is it legal to fish in this river?” “Yes, it's perfectly legal.”
The referee said it was a legal play.
Legally, they cannot do that.
The drug is legally bought and sold in many countries.
This agreement is legally binding.
He is legally blind. [=his vision is bad enough for him to be considered blind according to the law]
He was legally drunk. [=he was drunk according to the law]