Aven:

a'-ven ‘awen "emptiness," "vanity": Used in Eze 30:17 for On or Heliopolis, in Egypt. See ON. As a term of contempt Hosea calls Beth-el "Beth-aven" (4:15; 10:5). So Amos speaks of some valley near Damascus as "the valley of Aven" (that is, of the idol, 1:5), in which Baalbek (Heliopolis) was situated. The word is rendered "idol" in Isa 66:3.