The verb suffuse means to spread and fill a space, like the way the smell of wildflowers might suffuse a meadow.
Suffuse is a synonym for steep. Like tea whose flavor grows stronger the more it steeps, when you suffuse something it spreads throughout until an area is full, or even overly full. Another synonym, infuse, looks a lot like suffuse. Both words come from the Latin word fundere, which means "to pour."