What is the meaning of Theism?

Belief in the existence of at least one deity.

Belief in the existence of a personal creator god, goddess, gods and/or goddesses present and active in the governance and organization of the world and the universe. The God may be known by or through revelation.

A morbid condition resulting from excessive consumption of tea.

theism”, in The Century Dictionary [], New York, N.Y.: The Century Co., 1911, →OCLC.

theism, n.2”, in OED Online Paid subscription required, Oxford, Oxfordshire: Oxford University Press, 2015-03-18.

George M. Gould with R. J. E. Scott (1919) “theism”, in The Practitioner's Medical Dictionary, 3rd rev. and enl. edition, Philadelphia, Pa.: P. Blakiston's Son, →OCLC, page 883.

Source: wiktionary.org