Meaning of “rare” - Learner’s Dictionary

rare

adjective us uk /reər/
He spent several years researching a rare African dialect.The forest was populated by rare and colourful birds.He suffers from a rare genetic disorder.The shop specializes in rare books.It's very rare that a book is so good you laugh out loud.
UNUSUAL

B1 very unusual:

[ + to do sth ] It's very rare to see these birds in England.
MEAT

If meat is rare, it is still red because it has only been cooked for a short time:

a rare steak

(Definition of “rare” from the Cambridge Learner’s Dictionary © Cambridge University Press)