entries → 萬一
TSUMUGU · TOCFL B1 (est.) · 詞
萬一 word · TOCFL B1 (est.)
萬一 ＝ 萬 ＋ 一
ㄨㄢˋ ㄧ · wànyī
conjunction — just in case, if by chance; noun — a one-in-ten-thousand contingency

字源 FORM — what the parts do

萬ten thousand (萬歲)wàn
一one (一個)yī
萬一，萬歲的萬，一個的一。

故事 STORY — a scene to remember it by

一萬（萬）件事裡，就怕那一（一）件出錯。
Of ten thousand (萬) outcomes, it is the one (一) that goes wrong you guard against.
關 · Related
如果rúguǒplain 'if' — 萬一 is the worried, low-odds 'if'以防yǐfáng'so as to guard against' — the precaution 萬一 prompts