* A misspelling: Perhaps you meant a similar word like "listo" (Spanish for "ready").
* A regional term: It could be a slang or dialect word specific to a certain region.
* A proper noun: It might be the name of a person, place, or thing.
To get a more accurate answer, please provide more context:
* Where did you encounter this word? (e.g., a book, a website, a conversation)
* What was the sentence or phrase it was used in?
With more information, I might be able to understand the meaning of "lesto."