(Warning: may offend religious persons)
A slang, often used by Athiests/Agnostics (can also be used by other religions persons) to offend someone who believes anything that they read which has to do with thier current religion... when they cannot prove it true, and sound naive about it.
Mainly, pre-mature religious persons who are first exposed to the religion that are to be teached to them, are considered doafs, because they never reason and ask to PROVE it is true at first... unless they have an IQ over 9000!!!
At least 99.99999% of ALL Christians over the age of 18 are considered doafs.
A typical naive Christian, basicly.
"OMG that person believes that everything in the Bible is true... yet he can never PROOVE it is Gods word!? What a doaf."
You cannot prove that you naturally need to be Christian, when you are naturally born ATHIEST. Are you some kind of doaf or something???"