suffusion

1. He suffered from suffusion of blood on the brain.
   他患脑溢血。
2. The study on the formation model of collapse in covered karstic areas revealed that the process of karstic collapse includes actions of suffusion, vacuum suction and air explosion.
   对覆盖喀斯特区的塌陷形成模式的研究，得出塌陷的过程是潜蚀、吸蚀、气爆3种力的作用过程。

noun

1. the process of permeating or infusing something with a substance

   Synonym:    permeationpervasion