Definitions:

1. The act or process of spreading throughout or permeating every part of something. NOUN
   • The pervasion of a strange, unidentified smell throughout the house prompted a thorough investigation.
2. The process of permeating or infusing something with a substance. NOUN
   • The garden was notable for the pervasion of lavender scent that filled the air, creating a tranquil atmosphere.

Synonyms:

• diffusion
• dissemination
• engulfment
• impregnation
• Infiltration
• infusion
• propagation