真的沒接上
這一組是字面上的斷線：那條線真的沒接著。差別只在主角是人還是機器。
r · A2
With your computer or phone not connected to the internet. If you read, work, play or save something offline, you are doing it while the connection is switched off or not available.
離線地（沒連網路）
核心畫面
Two pieces, and the second one is the whole picture: off plus line. Think of a line running out of something and joining it to everything else — a cable out of a printer, a phone reaching the network, a conversation everyone in the room is plugged into. Being offline is down off that line. What changes across the senses is only which line is meant. Take away the internet and you get the everyday meaning. Take away the cable and you get the printer that will not print. Take away the shared conversation and you get the meeting-room slang. In every case, the thing is still there; it is just no longer joined.
可以想成兩個零件，而第二個零件就是整張圖：off 加上 line。想像有一條線從一樣東西伸出去，把它接到外面的世界。…更多收起
可以想成兩個零件，而第二個零件就是整張圖：off 加上 line。想像有一條線從一樣東西伸出去，把它接到外面的世界。印表機伸出一條線接到電腦。手機伸出一條線接到網路。開會的時候，所有人也接在同一條公共對話上。offline 就是從那條線上下來。各個意思之間變的只有「哪一條線」。斷掉網路那條，就是日常的「離線」。斷掉電腦那條，就是印表機不能印。斷掉公共對話那條，就變成會議室的行話。東西都還在，只是不再接著了。From the word’s history
Wiktionary gives the formation directly: off- + line. The word is built, not borrowed, and the two pieces still carry their ordinary meanings, which is why the picture above works for every sense.
來源字典直接寫明構成方式：off- 加上 line。這個字是組出來的，不是借來的。兩個零件到今天都還保有原本的意思，所以上面那張圖對每一個用法都成立。
Wiktionary (kaikki extract), entry 'offline', etymology_text: From off- + line.
Two branches
不在這條公共對話上
把那條線想成「大家都在聽的這場對話」，離開它就是私下談。這一步跳得比較遠，所以它常常是學習者誤會最深的一個用法。
r · C1
Away from the meeting or the group you are in, so that two or three people can settle something privately afterwards. This is office slang, and people use it even when everyone is sitting in the same room.
會後私下（談）