Spashed is a word used by someone to describe their own state of being after a large number of joints. The word comes from the inability of the mind to put the letter of a word together when stoned. So while you might have meant to say smashed (Which is a word to describe the state you would be in after drink anyway) your mind put in random letters to fill the space while your thinking about the word and you come up with "Spashed"
Aahh! Dude, I'm like amm!! what's it am like really (s..pa..shed)spashed man!