Learner's definition of BALD
of a person
having no hair or very little hair on the head
a bald man
All of his uncles are completely bald.
He's already starting to go bald. [=to become bald]
He had gone completely bald by the age of 30.
of a part of the body
not covered with hair
He covered his bald head with a baseball cap.
There's a bald spot on the top of his head.
There are bald patches in the cat's fur.
not covered with trees and plants
of a tire
having a flat and smooth surface because of age and use
said or given in a very direct way without extra details or explanations
She baldly asserted that her son was not guilty.
To put it baldly [=to say it in a harsh and honest way], I don't like you.