Noun---The outside part or uppermost layer of something (often used when describing its texture, form, or extent): "the earth's surface". Adjective----Of, relating to, or occurring on the upper or outer part of something: "surface workers at the copper mines". Verb----Rise or come up to the surface of the water or the ground: "he surfaced from his dive". Synonyms---Noun---superficies - face - area - top - plane - outside Synonyms---Adjective---superficial - skin-deep - shallow - sketchy - perfunctory CRUST Noun---The tough outer part of a loaf of bread. Verb---Form into a hard outer layer. Synonyms---rind - skin - peel.

Surface relates to the top or outside of something. Crust is a surface that is hard.

A crust refers to a hard outer shell around a softer inner material. For example, the surface of the earth is the earths crust. Bread has a hard outer crust.