N2 - 下線かせん
underline, underscore
N2 - 光線こうせん
beam, light ray
N2 - 新幹線しんかんせん
bullet train (very high speed), shinkansen
N2 - 線路せんろ
line, track, roadbed
N2 - 脱線だっせん
derailment, digression
N2 - 直線ちょくせん
straight line
N2 - 内線ないせん
phone extension, indoor wiring, inner line
N1 - 沿線えんせん
along railway line
N1 - 幹線かんせん
main line, trunk line
N1 - 三味線さみせん
three-stringed Japanese guitar, shamisen
N1 - 点線てんせん
dotted line, perforated line
N1 - 無線むせん
wireless, radio