Learner's definition of BALD
1 a of a person : having no hair or very little hair on the head
b of a part of the body : not covered with hair
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.
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.
2 : not covered with trees and plants 3 of a tire : having a flat and smooth surface because of age and use 4 : said or given in a very direct way without extra details or explanations