Aray is a defined term because it

has no width or depth

is described using an undefined term

has an informal definition

travels forever in one direction

A ray is a defined term because it  is described using an undefined term .

Step-by-step explanation:

In geometry , a ray is a line with begin from one single endpoint that is known as point of origin and that extends in one direction infinitely .

The three undefined terms in geometry :

1) point   2) line  3) plane

These undefined terms in geometry are use to define the other terms in geometry.

In the definition of ray we always use two undefined terms : a) line b) point

Thus, A ray is a defined term because it  is described using an undefined term.

the battle of gettysburg is considered the "high water mark" of the confederacy because it marked the greatest advance of the confederate forces against the union.