hepteract

As a noun hepteract is

(mathematics) a seven-dimensional hypercube.

As an adjective dimensional

is of or pertaining to dimensions.

As a noun hepteract is

(mathematics) a seven-dimensional hypercube.

As nouns the difference between seven and hepteract

is that seven is the digit/figure 7 or an occurrence thereof while hepteract is a seven-dimensional hypercube.

As a numeral seven

is a numerical value equal to 7; the number occurring after six and before eight.