arithmancy

• arithmomancy
• arithomancy
• arythmancy (early)

From Ancient Greek ἀριθμός (arithmós, “number”) +‎ -mancy.

arithmancy (uncountable)

1. Divination using numbers that are the equivalent of letters of a name
   • 1897, King James Daemonologie:

     "Of this roote last spoken of [astrology], springs innumerable branches; such as the knowledge of natiuities; the Chiromancie, Geomantie, Hydromantie, Arithmantie, Physiognomie: & a thousand others: which were much practiced, & holden in great reuerence by the Gentiles of olde."

   • 1920, Encyc. Occult, L. Spence:

     "Divination by means of numbers. The Greeks examined the number and value of the letters in the names of two combatants, and predicted that he whose name contained most letters, or letters of the greatest value, would be the victor."

• numerology

• arithmancy in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.