Why is it called spit roast?
From http://en.wikipedia.org/wiki/Rotisserie:


  Rotisserie is a style of roasting where meat is skewered on a spit – a long solid rod used to hold food while it is being cooked over a fire in a fireplace or over a campfire, or roasted in an oven.


A spit is a long solid rod :) (as confirmed by http://en.wiktionary.org/wiki/spit#Noun)