| 私 | sī | personal; private; selfish |
| 私人 | sī rén | private; personal; interpersonal; sb with whom one has a close personal relationship; a member of one's clique |
| 私有 | sī yǒu | private; privately-owned |
| 私有制 | sī yǒu zhì | private ownership of property |
| 国际私法 | guó jì sī fǎ | conflict of laws |
| 私营 | sī yíng | privately-owned; private |
| 走私 | zǒu sī | to smuggle; to have an illicit affair |
| 公私 | gōng sī | public and private (interests, initiative etc) |
| 公私合营 | gōng sī hé yíng | joint public private operation |
| 私法 | sī fǎ | private law |
| 自私 | zì sī | selfish; selfishness |
| 自私自利 | zì sī zì lì | everything for self and selfish profit (idiom); with no regard for others; selfish; mercenary |
| 私自 | sī zì | private; personal; secretly; without explicit approval |
| 无私 | wú sī | selfless; unselfish; disinterested; altruistic |
| 大公无私 | dà gōng wú sī | the common good above everything without no regard for personal interests (idiom); to behave altruistically; impartial and selfless; just and fair |
| 私下 | sī xià | in private |
| 私心 | sī xīn | selfishness; selfish motives |
| 私事 | sī shì | personal matters |
| 私家 | sī jiā | private; privately owned or managed |
| 营私 | yíng sī | to gain from corrupt dealing; to engage in graft; to feather one's nest |
| 私塾 | sī shú | private school (in former times) |
| 私藏 | sī cáng | secret store; a stash (of contraband) |
| 中饱私囊 | zhōng bǎo sī náng | to stuff one's pockets; to take bribes |
| 个人隐私 | gè rén yǐn sī | personal privacy; private matters |
| 假公济私 | jiǎ gōng jì sī | official authority used for private interests (idiom); to attain private ends by abusing public position |
| 偏私 | piān sī | to practice favoritism |
| 公报私仇 | gōng bào sī chóu | to use public office to avenge private wrongs |
| 公私交迫 | gōng sī jiāo pò | combined public and private interests are a powerful force (idiom) |
| 公私兼顾 | gōng sī jiān gù | public private partnership venture |
| 公而忘私 | gōng ér wàng sī | for the common good and forgetting personal interests (idiom); to behave altruistically; selfless |
| 切切私语 | qiè qiè sī yǔ | a private whisper |
| 反走私 | fǎn zǒu sī | to oppose smuggling; anti-contraband (measures, policy etc) |
| 官报私仇 | guān bào sī chóu | to take advantage of official post for personal revenge (idiom) |
| 官私合营 | guān sī hé yíng | public and private interests working together (idiom) |
| 徇私枉法 | xùn sī wǎng fǎ | to bend the law for one's own profit (idiom) |
| 徇私舞弊 | xùn sī wǔ bì | bribery and fraud (idiom) |
| 损公肥私 | sǔn gōng féi sī | to damage the public interest for personal profit (idiom); personal profit at public expense; venal and selfish behavior |
| 泄私愤 | xiè sī fèn | to vent personal spite; to act out of malice (esp. of crime) |
| 乌鸟私情 | wū niǎo sī qíng | lit. the solicitude of the crow (who provides for his old parent)(idiom); fig. filial piety |
| 营私舞弊 | yíng sī wǔ bì | fraudulent personal gain (idiom); to engage in corrupt practice |
| 私了 | sī liǎo | to settle privately; to solve behind closed doors; to settle out of court |
| 私人钥匙 | sī rén yào shi | private key (in encryption) |
| 私企 | sī qǐ | private enterprise; abbr. of 私营企业 |
| 私偏 | sī piān | selfish preference |
| 私利 | sī lì | personal gain; (one's own) selfish interest |
| 私募 | sī mù | private placement (investing) |
| 私募基金 | sī mù jī jīn | private equity fund; fund offered to private placement (e.g. hedge fund) |
| 私吞 | sī tūn | to misappropriate (public funds etc); to embezzle |
| 私囊 | sī náng | one's own pocket |
| 私奔 | sī bēn | to elope |