Of, relating to, or characteristic of gastriloquism or ventriloquism; having the quality of ventriloquial speech.
From Latin 'gaster' (stomach) and 'loqui' (to speak), combined with '-ous' (possessing the quality of). This adjective form developed alongside the noun forms in the 17th-18th centuries.
Using '-ous' instead of '-ial' to make an adjective shows how English loves synonyms—'gastriloquous,' 'gastriloquial,' and 'ventriloquial' all mean the same thing but sound subtly different!
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