Did Lucy Heartfilia and Zeref meet before the Eclipse Gate arc? I'm currently writing a fiction about Lucy Heartfilia and Zeref. I believe that she doesn't know what he looks like and that they didn't meet during the Tenrou Island Arc but I'm not 100% sure of it.

Did they meet before the Eclipse Gate arc?
No, Lucy never got the chance to look at Zeref.

Only Natsu, Elfman, Evergreen, Happy and Gray (in chapter 522, "Gray's Trump Card") have seen him. Lucy has heard of Zeref but never got a chance to see him.

However, towards the end of the manga series, Lucy does meet a Zeref look-a-like in chapter 545 (way after the Eclipse Gate Arc), "Friends you Can't do Without". The way he is portrayed was that he was a young writer attempting to meet with Lucy Heartfelia after her award ceremony. He picks up the handkerchief dropped by, what looks to me, Mavis Vermillion. They both engage in a conversation then leave, never to be seen for the remainder of the chapter.