完蛋
wán dàn · HSK 7
(coll.) to be done for
🥚 完蛋 = 完 (finish) + 蛋 (egg): your egg is finished, you're done for
完 means complete/finished and 蛋 means egg. Together the literal finish-the-egg reading became slang for being utterly done for, ruined, or out of luck.
完 — roof 宀 + yuán 元 (phonetic)
完 is a semantic-phonetic compound: the roof 宀 suggests a house or enclosure, while 元 supplies the sound 'yuán/wán'. Originally it meant a building that was intact or whole, and the sense broadened to 'complete, finish, whole'.
蛋 — top 疋 (cloth/foot) + bottom 虫 (insect/creature)
蛋 originally referred to an egg, with 虫 ('creature') as the semantic component indicating something laid by reptiles, birds, or insects. The upper 疋 element here functions largely as a phonetic marker rather than carrying meaning. Over time, 蛋 broadened from 'egg' to also mean a rounded, egg-shaped object.