What you say when someone says something that makes you think of something dirty or makes you think of sexually dirty innuendo. Or-when you hear something that makes you think of something dirty or sexual, "splash" is the sound "your mind makes when it falls into the gutter".
Jimmy said that the guy at the hotdog stand didn't like big wieners. so to respond to what Jimmy said, I yelled: Splash!
A cigarette rolled with approximately one part tobacco and one part hash. A variation on the common term spliff, meaning a cigarette rolled with marijuana and tobacco.