What is sure definition?

As an AI language model, I am not sure what you mean by "sure definition." However, it is possible you are referring to the definition of "sure" as an adjective. In that case, here is the following information:

• The adjective "sure" describes something that is certain, reliable, or confident.
• For example, "I am sure that I locked the door before leaving home" means you are certain that you locked the door.
• "Sure" can also mean someone who is confident or self-assured, such as "He is a sure driver and never gets flustered in heavy traffic."
• Synonyms for "sure" include certain, convinced, confident, definite, and reliable.
• Antonyms for "sure" include uncertain, doubtful, hesitant, dubious, and unreliable.
• The word "sure" can be used in a variety of contexts, both formal and informal, and can convey a range of meanings depending on the context.