1. pentagon(n = noun.artifact) - a government building with five sides that serves as the headquarters of the United States Department of Defense;
is a kind of government building
2. pentagon(n = noun.group) - the United States military establishment;
is a kind of bureaucracy, bureaucratism
3. pentagon(n = noun.shape) - a five-sided polygon;
is a kind of polygon, polygonal shape
A plane figure having five angles, and, consequently, five sides; any figure having five angles. [1913 Webster]
pentagon, n.
1 a plane figure with five sides and angles.
2 (the Pentagon) a the pentagonal Washington headquarters of the US defence forces. b the leaders of the US defence forces.
Derivative:
pentagonal adj.
Etymology:
F pentagone or f. LL pentagonus f. Gk pentagonon (as PENTA-, -GON)
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.