-theism

*dhēs-, Proto-Indo-European root forming words for religious concepts. Possibly an extension of PIE root *dhe- "to set, put."

It forms all or part of: apotheosis; atheism; atheous; Dorothy; enthusiasm; fair (n.) "a stated market in a town or city;" fanatic; ferial; feast; fedora; -fest; festal; festival; festive; festoon; Festus; fete; fiesta; henotheism; monotheism; pantheism; pantheon; polytheism; profane; profanity; Thea; -theism; theist; theo-; theocracy; theodicy; Theodore; Theodosia; theogony; theology; theophany; Theophilus; theosophy; theurgy; tiffany; Timothy.

It is the hypothetical source of/evidence for its existence is provided by: Greek theos "god;" Latin feriae "holidays," festus "festive," fanum "temple."

word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.