| 快 |
kuài xìn | letter sent by express mail |
| 快 |
kuài | rapid / quick / speed / rate / soon / almost / to make haste / clever / sharp (of knives or wits) / forthright / plainspoken / gratified / pleased / pleasant |
| 信 |
xìn | letter / mail / CL:封 / to trust / to believe / to profess faith in / truthful / confidence / trust / at will / at random |