Possible interpretations:
* "El otoño": This is the correct Spanish word for "autumn" or "fall".
* "El onto": This could be a misspelling of "el unto", which means "the ointment" or "the salve".
* "El ontono": This could be a regional dialect variation, but it is not commonly used in standard Spanish.
To understand the intended meaning, you'd need more context.
Can you provide more information about where you encountered this phrase? For example:
* The full sentence or passage: This would give more context about the subject matter.
* The source: Was it a book, website, conversation, etc.?
* The speaker or writer: Knowing their background or region can be helpful.
With more information, I might be able to give you a more accurate translation.