* A misspelling: Perhaps you meant a different word, like "salma," which means "safe" or "secure."
* A name: "Silma" could be a name, though it's not particularly common.
* A dialect-specific word: It might be a term used in a particular region or dialect of Arabic.
To get a clearer answer, please provide more context:
* What is the full phrase or sentence where you encountered "Silma"?
* What is the source of the word (e.g., a book, a conversation, a website)?
With more information, I might be able to help you understand the meaning of "Silma."