A ray is a line that has an originating point, but no end.
Yes it is
It is a ray [of coherent light], a physical term.
A ray is not an undefined term.
sile
You just defined a ray. ■
Erosion is the term that is defined as movement of soil by water or wind.
The term conserve can be defined as protecting from loss. It can also be defined as using something sparingly or being careful with something. Conserving energy for later use is an example using the term.
The U.S. Supreme Court has defined the term "search" to occur when
A Becquerel ray is an archaic term for any form of radioactive ray.
figurative
It is defined as person or citizen of the united states.
A ray is defined as having an origin but no endpoint (unless you count the origin as an endpoint, in which case it has 1).