* It's a misspelling: Could you be thinking of a different word? Perhaps a transliteration of a word from another language? Providing more context (like where you encountered this word) would be helpful.
* It's a dialectal word or a proper noun: Greek has many dialects, and "afta" might be a word used in a specific region or a name.
* It's not Greek: The word might belong to another language entirely.
Please provide more information for a more accurate answer.