| 笃 | dǔ | serious (illness); sincere; true |
| 笃信 | dǔ xìn | to believe firmly; devout in one's faith |
| 笃信好学 | dǔ xìn hào xué | sincere belief and diligent study |
| 笃厚 | dǔ hòu | honest and generous; magnanimous |
| 笃学 | dǔ xué | studious; diligent in study |
| 笃守 | dǔ shǒu | to comply faithfully; sincerely abiding by |
| 笃定 | dǔ dìng | certain; confident (of some outcome); calm and unhurried |
| 笃实 | dǔ shí | loyal; sincere; sound |
| 笃专 | dǔ zhuān | with undivided attention |
| 笃志 | dǔ zhì | steadfast; with single-minded devotion |
| 笃爱 | dǔ ài | to love deeply; devoted to sb |
| 笃挚 | dǔ zhì | sincere (in friendship); cordial |
| 笃病 | dǔ bìng | seriously ill; critical |
| 笃行 | dǔ xíng | to carry out (obligation) conscientiously; to behave sincerely |