DECAGON Antonyms There are 8 antonyms of the word decagon. (opposite meanings)Did you mean?Definition of DECAGONSynonyms of DECAGONBest Opposite Words For DECAGONTop 20Top 10 Top 20 (Default)Top 50 Top 100 All All (Default)WordsPhrases All All (Default)Verb Noun Adjective Adverb RankWordSave?Synonyms..UsageType1dodecagonnounn2heptagonnounn3hexagonnounn4nonagonnounn5octagonnounn6pentagonnounn7squareverb, nounv, n8triangleverb, nounv, n Alternatives for NONAGON Words (1)enneagonOpposite words for nonagon Alternatives for OCTAGON Words (2)eight-sidedoctagonalOpposite words for octagon Alternatives for PENTAGON Words (3)five-sidedheptagonhexagonPhrases (1)the pentagonOpposite words for pentagon Alternatives for SQUARE Words (19)straightsquarelybourgeoisfeatherhashnormalorthogonalperpendicularpiazzaplazasharptetragonfoursquareheartylamesatisfyingsolidstraightforwardsubstantialPhrases (6)carpenter's squarepound signpublic squaresecond powersquare toessquare upOpposite words for square Alternatives for TRIANGLE Words (5)bluebottletrigonwyetriangulumtrilateralOpposite words for triangle