Picture an arrow that has been shot properly but has landed off to one side. Nothing dramatic has happened, nothing has broken — it simply is not where it should be, and anyone watching can tell. That small gap between where a thing should sit and where it actually sits is what amiss keeps pointing at, whether the thing is a situation, an action, or a remark that reaches you the wrong way.
From the word’s history
Wiktionary analyses amiss as a- + miss. The miss inside it is the ordinary word for failing to hit something, which is exactly the off-target picture the modern uses keep.
Wiktionary 把 amiss 拆成 a- 加上 miss。裡面的 miss 就是「沒打中」的那個 miss，正好就是現在各種用法共有的「偏了一點」的畫面。
Wiktionary entry for amiss, kaikki extract kaikki:3f6f69a190036ae4:448388677:6370 (etymology: a- + miss)
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