千万 (qiān wàn) — (adverb) must, by all means (used in imperative sentences to emphasize necessity or prohibition)

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

千 pairs 人, whose sound was similar, with 一, a number stroke; the extra line was explained as extension, and a thousand is a number reached by extending counting.

A drawing of the thing itself, worn down over three thousand years into a few strokes.

This origin belongs to the traditional form 萬; 万 is its simplified writing.

For 万, the form 萬 was originally a picture of a scorpion, later borrowed for its sound to write 'ten thousand'; the scorpion picture is unrelated to that number.