Tumor and lump character

In Chinese, 瘤 means a tumor or abnormal tissue growth.

Mandarin reads it liú, roughly “lyoh” in one syllable with a rising tone. An early Chinese character dictionary, 說文解字, analyzes 瘤 as 疒, the illness radical, plus 留, which supplies its sound, and defines it as a swelling. Another old Chinese word dictionary, 釋名, links 瘤 to 流 (“flow”) and describes blood gathering into a lump; this is a historical word explanation, not a modern account of how tumors form. 癅 is an older written variant; 瘤 is the common modern form.

Chinese compounds make the medical meaning more specific: 腫瘤 means a tumor or tissue mass, while 肉瘤 names a sarcoma. 瘤 alone cannot tell you whether a growth is benign or malignant.

what does 瘤 mean in Japanese?

In Japanese, 瘤 can mean a physical bump or an obstacle.

For an everyday lump or knot, Japanese reads 瘤 as こぶ. A Japanese record from 750 already uses 瘤 for しいね, an old name for that kind of lump. Technical compounds can use the reading りゅう, as in 動脈瘤.

The idiom 目の上の瘤 (“a lump over the eye”) describes an unwelcome obstruction, such as a person or responsibility. The phrase turns a physical bump into a social metaphor.