Thinking: defining edge

Edge has many different meanings.

edge

ɛdʒ/

noun

1.     the outside limit of an object, area, or surface. "a willow tree at the water's edge"

synonyms: border, boundary, extremity, fringe, margin, side, lip, rim, brim, brink, verge, perimeter, circumference, periphery, contour, outline, limit, limits, outer limit, bound, bounds, bourn, skirt, "the edge of the lake"

2.     the sharpened side of the blade of a cutting implement or weapon. "a knife with a razor-sharp edge"

verb

1.     provide with a border or edge. "the pool is edged with paving"

synonyms: border, fringe, rim, verge, skirt, be alongside, surround, enclose, encircle, circle, encompass, bound, line, flank, "the tall poplars that edged the orchard", trim, pipe, band, decorate, finish, border, fringe, bind, hem, "a white party frock edged with lace"

2.     move or cause to move gradually or furtively in a particular direction, "she tried to edge away from him"

synonyms: creep, inch (one's way), worm (one's way), work (one's way), pick one's way, nose (one's way), ease (oneself), ease (one's way), advance slowly, advance stealthily, sidle, steal, slink, "he edged closer to the fire"

3.     give an intense or sharp quality to, "the bitterness that edged her voice"

4.   strike (the ball) with the edge of the bat; strike a ball delivered by (the bowler) with the edge of the bat, "he edged a ball into his pad"

5.     ski with one's weight on the edges of one's skis. "you will be edging early, controlling a parallel turn"

( https://www.google.com.au/search?client=safari&rls=en&q=edge+definition&ie=UTF-8&oe=UTF-8&gfe_rd=cr&dcr=0&ei=0u6VWuW1AY_r8wfAu4uADw, Accessed 28/2/18)

Edge (geometry)

In geometry, an edge is a particular type of line segment joining two vertices in a polygon, polyhedron, or higher-dimensional polytope. In a polygon, an edge is a line segment on the boundary, and is often called a side. In a polyhedron or more generally a polytope, an edge is a line segment where two faces meet. A segment joining two vertices while passing through the interior or exterior is not an edge but instead is called a diagonal.

(https://en.wikipedia.org/wiki/Edge_(geometry) Accessed 28/2/18)