This archaic adverb appears in historical, literary, or deliberately old-fashioned language.
I shall return anon.
The messenger promised to come again anon.
This internet and informal use abbreviates anonymous and may refer to an unidentified user or author.
The comment was posted by anon.
An anon user shared the image.
This rare historical use can mean at another moment, then, or later in a sequence.
Now he laughed, and anon he grew silent.
Anon the wind changed direction.
