Meaning
内線 (ないせん, naisen) is a JLPT N2 vocabulary word meaning “phone extension,indoor wiring,inner line”.
Kanji in this word
Example sentences 2
交換手です。内線番号をどうぞ。
Operator. Which extension would you like.
私の父は国内線のパイロットです。
My father is a pilot on the domestic line.