heptagonhep‧ta‧gon /ˈheptəɡən $ -ɡɑːn/ noun [countable] 
Word Origin
Word OriginWORD ORIGINheptagon
word setsOrigin:
1500-1600 Greek heptagonos, from hepta ‘seven’ + gonia ‘angle’WORD SETS► Maths
a shape with seven straight sides → polygon—heptagonal /hepˈtæɡənəl/ adjectiveabacus, nounalgebra, nounangle, nounarc, nounarea, nounarithmetic, nounarithmetic, adjectivearithmetic progression, nounaxis, nounbar chart, nounbar graph, nounbase, nounbinomial, nounbisect, verbBoolean, adjectiveC, nouncalculator, nouncalculus, nouncanonical, adjectivechord, nouncipher, nouncircumference, nouncircumscribe, verbcompass, nouncomplementary, adjectivecomputation, nouncompute, verbconcentric, adjectivecone, nouncongruent, adjectiveconical, adjectiveconstant, nouncontain, verbcoordinate, nouncoordinate, adjectivecos, cosine, nouncube, nouncubic, adjectivecurvature, nouncurve, nouncut, verbdeci-, prefixdeviation, noundiagonal, adjectivediameter, noundifferential calculus, noundigit, noundimension, noundomain, nouneccentric, adjectiveellipse, nounelliptical, adjectiveequal, adjectiveequal, verbequals sign, nounequation, nounequilateral triangle, nounexponential, adjectiveexpress, verbexpression, nounface, nounfigure, nounflow chart, nounformula, nounfraction, nounfractional, adjectivefunction, noungeometric, adjectivegeometry, noungraph, noungraphically, adverbgraph paper, noungrid, nounHCF, helix, nounheptagon, nounhexagon, nounhistogram, nounhypotenuse, nounimperial, adjectiveimproper fraction, nouninfinity, nouninformation theory, nouninnumerate, adjectiveinto, prepositioninverse, adjectiveisosceles triangle, nounline graph, log, nounlogarithm, nounlong division, nounlozenge, nounmath, nounmathematical, adjectivemathematician, nounmathematics, nounmatrix, nounmean, adjectivemedian, nounmedian, adjectivemetric, adjectiveminus, prepositionminus, nounminus, adjectiveminus sign, nounminute, nounmultiplication, nounmultiplication sign, nounmultiplication table, nounmultiply, verbN, nounnumber, nounnumerate, adjectivenumeration, nounoblong, adjectiveobtuse angle, nounoctagon, nounoval, nounparabola, nounparallel, adjectiveparallelogram, nounpentagon, nounpercentage, nounperimeter, nounperpendicular, nounpi, nounpictogram, nounpie chart, nounplane, nounplane geometry, nounplus, prepositionplus, nounplus, adjectiveplus sign, nounpolygon, nounpolyhedron, nounpower, nounprism, nounprobability, nounproof, nounproportion, nounproposition, nounprotractor, nounquadrangle, nounquadrant, nounquadratic equation, nounquadri-, prefixquadrilateral, nounradius, nounratio, nounrectangle, nounrectilinear, adjectiverecur, verbrhombus, nounright angle, nounright-angled triangle, nounroot, nounruler, nounscale, nounscalene triangle, nounscatter diagram, section, nounsegment, nounsemicircle, nounset square, nounsine, nounslide rule, nounsolid, adjectivesolid, nounsolution, nounsolve, verbsphere, nounsquare, adjectivesquare, nounsquare, verbsquare, adverbsquarely, adverbsquare root, nounsubset, nounsubtract, verbsubtraction, nounsum, nounsurface area, nounsymmetrical, adjectivesymmetry, nountangent, nounterm, nountheorem, nounthreefold, adjectivetimes, prepositiontrapezium, nountriangle, nountrigonometry, nountwo-dimensional, adjectivevalue, nounvariable, nounvector, nounVenn diagram, nounvertex, nounvertical, adjectivevolume, nounwork, verbX, nounx-axis, nouny-axis, noun