One way to hold this word: something is rubbing the same spot, again and again, and it never stops long enough for the spot to settle. Each single touch is nothing. The is what does the damage. Hold that picture and both halves of the word follow — a chemical rubbing at your skin until it turns red, and a dripping tap rubbing at your week until you cannot hear anything else. Notice the size limit built into the picture: rubbing makes a place sore, it does not knock anything down.
From the word’s history
The packet's source gives the word as French irritant, equal to irritate plus -ant: the thing that does the irritating.
packet 的詞源說這個字來自法文，等於 irritate 加上 -ant。-ant 可以想成「會做那件事的東西」。所以它一開始指的就是「會 irritate 的那個東西」，後來這個「東西」從物質擴到了事情。
packet Wiktionary etymology_text (kaikki:3f6f69a190036ae4:1141922063:5826)
登入就可以看每一支怎麼連回核心畫面。