Figure of Speech
Apostrophe
From Greek apostrophe: turning away (from the audience to address another). Ubiquitous in ode, elegy, and lyric; central to Romantic invocations of nature.
Definition
Direct address to an absent, dead, abstract, or inanimate entity as though it were present and capable of response.
Example
'O Death, thou comest when I had thee least in mind.' (Everyman, medieval morality play)