The term 'accepted principle' can be broken down into two crossword solutions: CANON (5 letters) and AXIOM (5 letters). A CANON is a rule or principle that is widely accepted and followed, while an AXIOM is a self-evident truth or a statement that is accepted without proof. Both terms refer to a set of beliefs or principles that are widely accepted and followed. CANON and AXIOM are often used interchangeably, but they have slightly different meanings. CANON is more often used to refer to a set of rules or principles that are widely accepted and followed, while AXIOM is more often used to refer to a self-evident truth or statement.