Stand at the edge of the sea. The surface is flat and looks safe, but underneath it a body of water is moving steadily, sometimes the opposite way from the . You cannot see it. You only find out it is there by feeling it, and often only after it has already moved you. Both meanings of the word live inside that one picture: the water itself, and the feeling that keeps moving through a group of people while the surface stays polite.
From the word’s history
The packet's Wiktionary entry gives the word as under- + current, so the shape of the word is the picture itself: the current that is under. English later used the same shape for feelings.
評估資料裡的 Wiktionary 記的是 under- 加 current。這個字的組成本身就是那個畫面：在底下的那股水流。後來英文把同樣的組合拿去講情緒。
Wiktionary etymology supplied in this evidence packet (source_ref kaikki:3f6f69a190036ae4:1046638274), text: 'From under- + current.'
登入就可以看每一支怎麼連回核心畫面。