Curiously pro-Amish saying (8)
I believe the answer is:
aphorism
'saying' is the definition.
(I know that aphorism is a type of axiom)
'curiously pro-amish' is the wordplay.
'curiously' indicates an anagram.
'pro'+'amish'='proamish'
'proamish' with letters rearranged gives 'APHORISM'.
(Other definitions for aphorism that I've seen before include "Short, clever saying" , "Saw" , "Maxim, short wise saying" , "A short, pithy, instructive saying" , "Adage" .)