| 刻骨相思 | kè gǔ xiāng sī | lit. one’s feelings carved into one’s bones; to care for sb very deeply (idiom) |
| 劳心苦思 | láo xīn kǔ sī | to rack one's brains; to think hard |
| 匪夷所思 | fěi yí suǒ sī | fantastic; freak (accident etc) |
| 博斯沃思 | Bó sī wò sī | Bosworth (name); Stephen Bosworth (1939-), US academic and diplomat, special representative for policy on North Korea from 2009 |
| 卡尔・马克思 | Kǎ ěr · Mǎ kè sī | Karl Marx (1818-1883), German socialist philosopher, political activist and founder of Marxism |
| 史思明 | shǐ sī míng | Shi Siming (703-761), non-Han military man and colleague of An Lushan 安禄山, eventually conspirator with him in the 755-763 Anshi rebellion 安史之乱 against the Tang dynasty |
| 味美思酒 | wèi měi sī jiǔ | vermouth (loanword); Italian spiced fortified wine |
| 哀思 | āi sī | grief-stricken thoughts; mourning |
| 善思 | shàn sī | thoughtfulness; wholesome thinking (Buddhism) |
| 单相思 | dān xiāng sī | one-sided lovesickness; unrequited longing |
| 姚思廉 | Yáo Sī lián | Yao Silian (557-637), Tang writer and compiler of 梁书 and 陳書 陈书 |
| 字面意思 | zì miàn yì si | literal meaning |
| 孝思不匮 | xiào sī bù kuì | to be forever filial (idiom) |
| 孟思诚 | Mèng Sī chéng | Maeng Saseong (1360-1438), Korean politician of the Goryeo-Joseon transition, famous for his honesty and wisdom |
| 孙思邈 | Sūn Sī miǎo | Sūn Sīmiǎo (c. 581-682), doctor and herbalist of the Sui and Tang dynasty, author of Prescriptions Worth a Thousand in Gold 千金要方 |
学而不思则罔，
思而不学则殆 | xué ér bù sī zé wǎng ,
sī ér bù xué zé dài | To learn without thinking is blindness, to think without learning is idleness (Confucius).; Learning without reasoning leads to confusion, thinking without learning is wasted effort. |
| 害相思病 | hài xiāng sī bìng | sick with love |
| 封建思想 | fēng jiàn sī xiǎng | feudal way of thinking |
| 尤里斯・伊文思 | Yóu lǐ sī · Yī wén sī | Joris Ivens (1898-1989), Dutch documentary filmmaker and committed communist |
| 居安思危 | jū ān sī wēi | to think of danger in times of safety; to be vigilant in peacetime (idiom) |
| 左思 | Zuǒ Sī | Zuo Si (3rd century), Jin dynasty writer and poet |
| 左思右想 | zuǒ sī yòu xiǎng | to turn over in one's mind (idiom); to think through from different angles; to ponder |
| 巴克科思 | Bā kè kē sī | Bacchus, Roman God of wine |
| 希思罗 | Xī sī luō | Heathrow (a London airport) |
| 康思维恩格 | Kāng sī wéi ēn gé | Kongsvinger (city in Hedemark, Norway) |
| 忖思 | cǔn sī | to reckon; to consider; to ponder; to estimate |
| 思之心痛 | sī zhī xīn tòng | a thought that causes heartache (idiom) |
| 思南 | Sī nán | Sinan county in Tongren prefecture 铜仁地区, Guizhou |
| 思南县 | Sī nán xiàn | Sinan county in Tongren prefecture 铜仁地区, Guizhou |
| 思情 | sī qíng | to miss; to long for |
| 思想交流 | sī xiǎng jiāo liú | exchange of ideas |
| 思想包袱 | sī xiǎng bāo fu | a load on one's mind |
| 思想史 | sī xiǎng shǐ | intellectual history |
| 思想库 | sī xiǎng kù | think tank (committee set up to study a problem) |
| 思想意识 | sī xiǎng yì shí | consciousness |
| 思想素质 | sī xiǎng sù zhì | quality of thought (in ideological education) |
| 思想顽钝 | sī xiǎng wán dùn | blunt thinking; apathy |
| 思慕 | sī mù | to cherish the memory of sb; to think of with respect |
| 思恋 | sī liàn | to miss; to long for |
| 思明 | Sī míng | Siming district of Xiamen city 厦门市 (Amoy), Fujian |
| 思明区 | Sī míng qū | Siming district of Xiamen city 厦门市 (Amoy), Fujian |
| 思科 | Sī kē | Cisco Systems Company |
| 思维敏捷 | sī wéi mǐn jié | quick-witted; agile of mind |
| 思茅 | Sī máo | Simao city in Yunnan, renamed Pu'er city 普洱市 in 2007 |
| 思茅区 | Sī máo qū | Simao district of Pu'er city 普洱市, Yunnan |
| 思茅地区 | Sī máo dì qū | Simao prefecture in Yunnan |
| 思茅市 | Sī máo shì | Simao city in Yunnan, renamed Pu'er city 普洱市 in 2007 |
| 思亲 | sī qīn | to remember one's parents; to feel homesick for one's relatives |
| 思谋 | sī móu | to consider; to turn over in one's mind |
| 思议 | sī yì | to imagine; to comprehend |
