\begin{definition}[Definition:Line/Endpoint]
Each of the points at either end of a line segment is called an '''endpoint''' of that line segment.
Similarly, the point at which an infinite half-line terminates is called '''the endpoint''' of that line.
{{EuclidSaid}}
:''{{:Definition:Euclid's Definitions - Book I/3 - Line Extremities}}''
{{EuclidDefRefNocat|I|3|Line Extremities}}
\end{definition}