In the bible, anointing generally refers to the kind of ceremony where something or somebody is marked as sacred by pouring oil on it. For example, becoming a king usually involves the ceremony of pouring oil on the new king's head. And in the Catholic church, there's a ceremony called the Anointing of the Sick, during which a priest pours holy oil on a sick person’s head to elicit the God's healing power. In this passage, Robin uses the same word Oberon when describing his plan to pour the love juice on Demetrius' eyes. Today we mostly use anoint in a figurative sense to describe someone who’s chosen as if by God for some office or position, as in, "she was anointed by the party bigwigs to be their presidential candidate" – no oil needed.