Antonyms of noun parallelogram

1 sense of parallelogram

Sense 1
parallelogram -- (a quadrilateral whose opposite sides are both parallel and equal in length)
       Antonym of trapezium (Sense 1)
      => trapezium -- (a quadrilateral with no parallel sides)

Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun parallelogram

1 sense of parallelogram

Sense 1
parallelogram -- (a quadrilateral whose opposite sides are both parallel and equal in length)
       => quadrilateral, quadrangle, tetragon -- (a four-sided polygon)