- The study of the appearance and behavior of spiders, or the patterns of their webs (possibly related to the third meaning) for use in divination.
- The ability to take control over spiders with the intent to use them for attacking purposes or similar purposes.
- Also the divination of patterns, for example in geometric patterns, and tapestries.
- Possibly also the creation of a view using scientific results by separating, and combining of new research.
From arachno- + -mancy.