Hermeticism or hermetics is a set of philosophical and religious views and concepts, based mainly on Hellenistic-Roman pseudoepigraphic writings, attributed to Herm Trismegistus (ancient Gr. Her ideas are fundamentally influenced by the Western magical tradition and the Italian Renaissance. Herm's cult appeared in Islam around 830 AD. among the Sabians mentioned in the Qur'an.
The word comes from the Latin adjective hermeticus "hermetic", or "Hermov" (eg hermetic writings). A follower of hermeticism is called a hermetic. The term hermetic (plural hermetic) in the broadest sense means any subject relating to hermeticism. In the narrower sense, e.g. in philology, denotes a preserved or lost hermetic text document.