TSUMUGU · B2 (est.) · 字
爛
爛 ＝ 火 ＋ 闌
ㄌㄢˋ · làn
adj — soft-cooked, overripe, rotten; brilliant
字源 FORM — what the parts do
闌聲lán — gives the sounda gate (門) with 柬 barring it
Tlán → làn — only the tone tips down
Fire (火) cooking a thing past firm — soft, falling apart, gone bad. 闌 lán carries the sound, the tone tipped down; here it stands in for 蘭, leveled by clerical copying. From thorough cooking comes brightness too: 煮爛、腐爛、燦爛.
故事 STORY — a scene to remember it by
一鍋肉用火（火）燉到一夾就散，入口即化——爛。
A pot of meat cooked over fire (火) until a pinch pulls it apart, melting on the tongue — done soft.
字源記憶法
意 · Meanings
(本義)煮爛、軟爛— soft-cooked, tender常用
→腐爛— to rot, go bad
⇒燦爛— brilliant, dazzling
(本義) original meaning · → ⇒ each arrow = one more step of extension
關 · Related
闌lánthe phonetic alone — the barred gate, no fire yet瀾lánthe kin — 瀾 sets beside water 氵 (a wave); 爛 beside fire
演 · Evolution
說文以蘭加火寫此字。隸變把蘭抹平成闌，今日的爛便留著這道門柵的形——草字頭早沒了。
說文 writes the word with 蘭 above the fire. Clerical copying leveled 蘭 to 闌, and the modern 爛 keeps that barred-gate shape — no grass left in it.