| 膝 | xī | knee |
| 膝盖 | xī gài | knee |
| 促膝 | cù xī | lit. knees pressed close; intimate; seated side by side; in close contact |
| 促膝谈心 | cù xī tán xīn | to sit side-by-side and have a heart-to-heart talk (idiom) |
| 卑躬屈膝 | bēi gōng qū xī | to bow and bend the knee (idiom); fawning; bending and scraping to curry favor |
| 奴颜婢膝 | nú yán bì xī | servile and bending the knee (idiom); fawning; bending and scraping to curry favor |
| 屈膝礼 | qū xī lǐ | curtsy |
| 牛膝 | niú xī | Achyranthes bidentata (root used in Chinese medicine) |
| 牛膝草 | niú xī cǎo | hyssop (Hyssopus officinalis) |
| 男人膝下有黄金 | nán rén xī xià yǒu huáng jīn | lit. the man has gold under his knees; fig. a man who does not easily kneel in front of others (owing to pride or moral integrity) |
| 绕膝 | rào xī | (children) run around parent's knees; fig. to stay to look after one's elderly parents |
| 绕膝承欢 | rào xī chéng huān | to live with one’s parents thus bringing them happiness (idiom) |
| 膝上型 | xī shàng xíng | laptop (computer) |
| 膝上型电脑 | xī shàng xíng diàn nǎo | laptop (computer) |
| 膝下 | xī xià | at the knee (in reference to children); (salutation used in letters to parents or grandparents) |
| 膝袒 | xī tǎn | to walk on one's knees and bare one's breast (a gesture of deepest apology) |
| 护膝 | hù xī | kneepad; knee brace |
| 双膝 | shuāng xī | both knees |
