Gematria (Heb.) A division of the practical Kabbalah. It shows the numerical value of Hebrew words by summing up the values of the letters composing them and further, it shows by this means, analogies between words and phrases. [w.w.w.]
One of the methods (arithmetical) for extracting the hidden meaning from letters, words and sentences.
Source: H.P.Blavatsky - The Theosophical Glossary