Irfan also spelt eerfan (Arabic/Persian/Urdu: عرفان) literally means knowing. Sometimes it is transliterated as Erfan. It is used to refer both to Islamic mysticism as well as the attainment of direct spiritual knowledge. In the latter sense it is often translated in English as gnosis. Those with the name are sometimes referred to as having an insight into the unseen.
In Twelver Shi'a Islam, the term refers specifically to the discipline of mystical knowledge within religious teachings. In this respect Irfan overlaps considerably with Sufism in both meaning and content. (http://en.wikipedia.org/wiki/Irfan)