"study of the occult meaning of numbers, divination by numbers," 1911, a hybrid from Latin numerus "a number" (see number (n.)) + Greek -logia (see -logy). A correct formation would be arithmology, from Greek arithmos "number." Related: Numerological; numerologist.
numerate
numeration
numerative
numerator
numerical
numerology
numerosity
numerous
Numidia
numinous
numismatic