Picture a truck backed up to the door of a shop. The doors open, and everything that was riding on it comes off and stands on the ground. The truck drives away lighter. Every use of offload grows out of that one moment: a load that was yours is now somewhere else. Sometimes the load is boxes or sacks. Sometimes it is stock nobody will buy, a job you do not want, a worry you have carried for weeks, or a ball you cannot run with any further. The vehicle in the picture is often you.
可以想成一台倒車停在店門口的貨車。門一打開，本來載著的東西全部下來、站在地上，車子開走的時候就輕了。offload 的各種用法，都像是從這一刻長出來的：本來壓在你這邊的東西，現在在別的地方了。有時候卸下來的是箱子、是米袋；有時候是賣不掉的存貨、不想做的工作、扛了好幾個星期的煩惱，或是手上再也帶不動的那顆球。畫面裡那台車，很多時候就是你自己。
From the word’s history
The word is simply off plus load, so its shape already is the picture: the load goes off.
這個字就是 off 加上 load，字的形狀本身就是那個畫面：載著的東西離開。
Wiktionary entry for offload, source_ref kaikki:3f6f69a190036ae4:1147145816, etymology_text: From off- + load.
登入就可以看每一支怎麼連回核心畫面。