n.1 a point at which two or more things are joined.
2 a place where two or more railway lines or roads meet, unite, or cross.
3 the act or an instance of joining.
4 Electronics a region of transition in a semiconductor between regions where conduction is mainly by electrons and regions where it is mainly by holes.
Phrases and idioms:
junction box a box containing a junction of electric cables etc.
Etymology: L junctio (as JOIN)