Extension, prolongation, or lengthening (of time, distance, etc.). Often used as a noun or with suru: 'to extend'.
会議の時間をあと30分延長することに決めた。
We decided to extend the meeting by another 30 minutes.
工事は悪天候のため延長された。
The construction was extended due to bad weather.
延長コードを使ってテレビをコンセントにつないだ。
I used an extension cord to plug the TV into the outlet.
期限の延長を申請したが、まだ返事が来ていない。
I applied for an extension of the deadline, but I haven't received an answer yet.
Total length or overall extension (e.g., the total length of a road or railway).
この鉄道路線の延長は約50キロメートルだ。
The total length of this railway line is about 50 kilometers.
公園の遊歩道の延長を測定して報告書に記載した。
I measured the total length of the park's promenade and recorded it in the report.
An extension or continuation of work/activities (e.g., extending a deadline or continuing work).
納期の延長を会社に相談した。
I consulted the company about extending the deadline.
作業の延長により、チームの残業が増えた。
Because the work was extended, the team's overtime increased.
Extension in mathematics: extending a line segment or curve, or the extension of sets/functions (a technical mathematical usage).
まず線分ABの延長を考えて、交点を求める。
First consider the extension of segment AB and find the intersection point.
In philosophy, 'extension' — the property of occupying space or the spatial extent of an object (a conceptual usage).
デカルトの哲学では物質の本性としての延長が重要な概念だ。
In Descartes' philosophy, extension as a property of matter is an important concept.
The Enchō era (a Japanese era name): the period from April 923 to April 931 (historical usage).
延長年間の史料を研究して、その時代の社会状況を明らかにした。
By studying documents from the Enchō years, I clarified the social conditions of that period.
Overtime or extra time in sports: a period when a game continues beyond the regular time (e.g., an extra inning or overtime period).
試合は延長に入り、最後はPK戦で決着がついた。
The match went into extra time, and finally was decided by a penalty shootout.
昨日の野球の試合は延長で10回まで続いた。
Yesterday's baseball game went into extra innings and lasted until the 10th.