在水面撥動
這一組就是核心畫面本身，水是真的水。
verb · B2
To move your hands, feet, or fingers about in water, slowly and usually for pleasure. The part of your body stays near the surface, and the water moves and splashes a little.
（把手腳）在水裡撥動
核心畫面
One way to hold this word: a hand or a foot moving lightly about in shallow water. The movement is small and repeated, it happens at the surface, and nothing ever goes right under. You can stop at any moment and walk away dry. Every other use of dabble keeps that picture and changes only what the water is.
dabble 的畫面可以想成：一隻手或一隻腳，在淺水裡輕輕撥來撥去。動作很小，一下一下的，而且都停在水面那一層。從頭…更多收起
dabble 的畫面可以想成：一隻手或一隻腳，在淺水裡輕輕撥來撥去。動作很小，一下一下的，而且都停在水面那一層。從頭到尾沒有整個人下去。想停隨時可以停，起身還是乾的。它其他的用法，都可以看成同一個畫面，只是把「水」換成別的東西。From the word’s history
The source traces dabble to earlier dable, which is dab (a light tap) plus the frequentative ending -le, so the literal idea is tapping lightly again and again; it may be connected to Middle Dutch dabbelen.
字源資料把 dabble 拆成 dab（輕輕拍一下）加上表示「反覆做」的字尾 -le，字面就是「一下一下地輕拍」。這條線索跟水面撥動的核心畫面完全對得上，也解釋了為什麼引申義會是「只碰一下下」。另外也可能跟中古荷蘭文的 dabbelen 有關。
Wiktionary (kaikki extract, source_ref kaikki:3f6f69a190036ae4:1176969838:34773): "From earlier dable, equivalent to dab + -le (frequentative suffix), possibly from Middle Dutch dabbelen"
Two branches
只碰一點點的投入
把水換成一件事，人就成了那隻手：只在表面碰一碰，沒有跳進去。
verb · B2
To take part in an activity a little, and in a way that is not serious. You try it now and then, for fun or interest, without going deep into it or making it your main work.
涉獵、玩票