say it: rek-TANGG-yuh-lur
rectangular is an adjective meaning "having four right angles". It carries 2 recorded senses.
having a set of mutually perpendicular axes; meeting at right angles
“wind and sea may displace the ship's center of gravity along three orthogonal axes”
“a rectangular Cartesian coordinate system”
Definitions, synonyms and semantic relations for rectangular come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.