烂
làn · HSK 5
rot
🔥 烂 = 火 (fire) + 阑 (lán, phonetic) — fire-rotted, charred to mush
The 火 radical signals fire/heat damage; 阑 supplies the làn sound. Together they mark something cooked or burnt past usefulness — rotten, sodden, festering. Modern slang extends it to 'crappy' or 'lousy'.
烂 — fire radical 火 + 阑 (lán, phonetic)
A semantic-phonetic compound: 火 (fire) gives the meaning, while 阑 supplies the sound 'lán'. The original sense was 'cooked soft by fire,' as in overboiled food falling apart. From there it extended to 'rotten, mushy, worn out,' and figuratively to 'lousy' or 'terrible.'