dictionary - What is the meaning of ー・

Can someone tell me what the notation "ー・" means?

It's all over this article: 大辞林「いう【言う・云う・謂う】」

Answer

It simply means that it should be replaced by 言, 云 or 謂 in actual usage.

The notation is used exclusively in some dictionaries to avoid looking repetitive in giving example phrases/sentences for the entry word.

(Of course, one could argue that the use of the same notation over and over looks repetitive, too.)