Definitions:
find or discover by investigation

copy (a drawing, map, or design) by drawing over its lines on a superimposed piece of transparent paper

a mark, object, or other indication of the existence or passing of something

a very small quantity, especially one too small to be accurately measured

a procedure to investigate the source of something, such as the place from which a telephone call was made

a line which represents the projection of a curve or surface on a plane or the intersection of a curve or surface with a plane.

a path or track.

the sum of the elements in the principal diagonal of a square matrix.

each of the two side straps, chains, or ropes by which a horse is attached to a vehicle that it is pulling