Word Study
heptagon
CIDE DICTIONARY
heptagon, n. [Gr. sevencornered; "epta` seven + angle: cf. F. heptagone.].
A plane figure consisting of seven sides and having seven angles. [1913 Webster]
OXFORD DICTIONARY
heptagon, n. a plane figure with seven sides and angles.
Derivative
heptagonal adj.
Etymology
F heptagone or med.L heptagonum f. Gk (as HEPTA-, -GON)
ROGET THESAURUS
heptagon
Angularity
N angularity, angularness, aduncity, angle, cusp, bend, fold, notch, fork, bifurcation, elbow, knee, knuckle, ankle, groin, crotch, crutch, crane, fluke, scythe, sickle, zigzag, kimbo, akimbo, corner, nook, recess, niche, oriel, coign, right angle, obliquity, angle of 45 degrees, miter, acute angle, obtuse angle, salient angle, reentering angle, spherical angle, angular measurement, angular elevation, angular distance, angular velocity, trigonometry, goniometry, altimetry, clinometer, graphometer, goniometer, theodolite, sextant, quadrant, dichotomy, triangle, trigon, wedge, rectangle, square, lozenge, diamond, rhomb, rhombus, quadrangle, quadrilateral, parallelogram, quadrature, polygon, pentagon, hexagon, heptagon, octagon, oxygon, decagon, pyramid, cone, Platonic bodies, cube, rhomboid, tetrahedron, pentahedron, hexahedron, octahedron, dodecahedron, icosahedron, eicosahedron, prism, pyramid, parallelopiped, curb roof, gambrel roof, mansard roof, angular, bent, crooked, aduncous, uncinated, aquiline, jagged, serrated, falciform, falcated, furcated, forked, bifurcate, zigzag, furcular, hooked, dovetailed, knock kneed, crinkled, akimbo, kimbo, geniculated, oblique, fusiform, wedge-shaped, cuneiform, cuneate, multangular, oxygonal, triangular, trigonal, trilateral, quadrangular, quadrilateral, foursquare, rectangular, square, multilateral, polygonal, cubical, rhomboid, rhomboidal, pyramidal.For further exploring for "heptagon" in Webster Dictionary Online