surface

The overside or up-side of a flat object such as a table, or of a liquid.

The outside hull of a tangible object.

Outward or external appearance.

“On the surface, the spy looked like a typical businessman.”

The locus of an equation (especially one with exactly two degrees of freedom) in a more-than-two-dimensional space.

(fortification) That part of the side which is terminated by the flank prolonged, and the angle of the nearest bastion.

To provide something with a surface.

To apply a surface to something.

To rise to the surface.

To bring to the surface.

To come out of hiding.

For information or facts to become known.

To make information or facts known.

To work a mine near the surface.

To appear or be found.