Picture one thin, hard little point — the kind that runs along a rose stem or covers a hedgehog's back. It is too small to wound anyone. What it does is sting the skin for a second and then let go. Almost everything else this word does can be felt from that one small sting: skin that stings under rough wool, eyes that sting just before tears, and the quick cold feeling that runs over you when you are suddenly afraid or . The point becomes a feeling, and the feeling keeps the point's size — small, sharp, and quickly over.
The supplied source traces prickle to Old English pricel, analysable as prick plus the ending -le, which carries a sense of smallness. The literal reading is a little prick — which is exactly the size the modern word keeps, in the thing and in the feeling alike.
提供的資料把 prickle 追到古英文 pricel，可以拆成 prick（扎）加上帶「小」味道的字尾 -le。字面上就是「小小的一扎」。這個份量一路留到今天：不管講的是實物的刺，還是身上的感覺，都維持著「小而尖、一下就過」的大小。
Wiktionary etymology supplied in this packet (kaikki extract, source_ref kaikki:3f6f69a190036ae4): Middle English prykkyl, Old English pricel; by surface analysis prick + -le.
Three branches
扎人的小尖刺（看得到、摸得到）
這一組就是核心畫面本身：真的長在植物或動物身上、伸手會碰到的那種細小尖刺。
noun · B2
A small, thin, sharp point that grows on the surface of a plant, such as a rose or a cactus, or on the skin of an animal, such as a hedgehog. It is sharp enough to sting your skin if you touch it, but too small to make a deep cut.
刺；尖刺
皮膚被扎到的刺麻感
把刺拿掉，只留下它碰到皮膚的那一瞬間，就得到這一組：東西扎人、皮膚發麻、眼睛發酸，都是同一個感覺換了位置。
verb · B2
If your skin prickles, it starts to sting or tingle slightly — for example because of heat, cold, or rough cloth touching it.
（皮膚）刺刺麻麻
情緒像從裡面扎了一下
這一組把刺移到身體裡面：害怕或興奮冒上來時往皮膚扎一下，所以感覺跟被刺到一樣涼、一樣快。這是教學上的連結，不是在說歷史上先有哪個意思。
noun · C1
A short, slight feeling of fear, anger, or excitement that you notice on your skin as a cold, uncomfortable tingle. It is almost always used as a prickle of + the feeling.
一陣（寒意般的情緒）