bush baptist

noun2

1. •
   (slang) A fictitious religious affiliation, invoked by a person who does not claim or admit affiliation with a particular church.

   • I asked Jim what religion he was, and he replied "bush baptist".
2. •
   (slang) A person not educated in any particular religion; a religious zealot or proselytiser not educated in religion.

   • Annesley knew this meant that she was not to tell tales, but about what? Did Uncle Walker want his Bush Baptist religion kept a secret? — 1975