octagon

noun 0.728

heptagon

noun 0.718

decagon

noun 0.711

tetragon

noun 0.687

hexagon

noun 0.682

dodecagon

noun 0.646

pentagon

noun 0.625

regular polygon

noun 0.606

nonane

noun 0.580

nonet

noun 0.578

agon

noun 0.554

chiliagon

noun 0.553

ennead

noun 0.546

octuple

noun 0.539

octant

noun 0.535

octahedron

noun 0.533

polygon

noun 0.533

octad

noun 0.532

octa

noun 0.530

heptad

noun 0.514

pentangle

noun 0.514

pentomino

noun 0.513

quadrangle

noun 0.512

agonic

noun 0.505

nonamer

noun 0.503

ninth

noun 0.502

nonagenarian

noun 0.502

hexad

noun 0.501