Expanse /(?)/

Ex·panse

Expanse

n.
  1. That which is expanded or spread out; a wide extent of space or body; especially, the arch of the sky.
    Lights . . . high in the expanse of heaven.
    The smooth expanse of crystal lakes.

Expanse

v. t.
  1. To expand. [Obs.]
    That lies expansed unto the eyes of all.