noun, noun which may take the genitive case particle 'no'
branch line; spur line
Refers to a secondary railway line that branches off from a main line. Also used figuratively for other branching connections.
この支線は本線から分岐している。
This branch line diverges from the main line.
支線の駅は小さくて静かだ。
The station on the branch line is small and quiet.
幹線 is the main trunk line of a network, whereas 支線 is a branch line that splits off from it.
本線 is the main line of a railway or network, while 支線 is a branch line that splits off from it.
Compound of 支 (branch, support) and 線 (line). The kanji combination directly conveys the meaning of a branching line.