| 似 | sì | to seem; to appear; to resemble; similar; -like; pseudo- |
| 似乎 | sì hū | apparently; to seem; to appear; as if; seemingly |
| 似的 | shì de | seems as if; rather like |
| 似是而非 | sì shì ér fēi | apparently right but actually wrong; specious (idiom) |
| 似笑非笑 | sì xiào fēi xiào | like a smile yet not a smile (idiom) |
| 似懂非懂 | sì dǒng fēi dǒng | seem to understand, but not understand (idiom) |
| 似曾相识 | sì céng xiāng shí | déjà vu (the experience of seeing exactly the same situation a second time); seemingly familiar; apparently already acquainted |
| 似核 | sì hé | nucleoid (of prokaryotic cell) |
| 似雪 | sì xuě | snowy |
| 似鸟 | sì niǎo | bird-like |
| 似鸟恐龙 | sì niǎo kǒng lóng | ornithischian; bird-like dinosaur |