KEY: Paradox.
SYN: Contradiction, enigma, mystery, absurdity, ambiguity.
ANT: Precept, proposition, axiom, truism, postulate.

• Referee
• Reference
• Refined
• Refinement
• Refit
• Refix
• Reflect
• Reflection
• Reform
• Reformation
• Refraction
• Refractory
• Refragable
• Refrain
• Refresh
• Refreshment
• Refuge
• Refund
• Refuse
• Refuse \v
• Refutable, [See REFRAGABLE]
• Refute
• Regain
• Regal \a
• Regale