Synonyms for Axiomatic (same or very similar meaning)
WordNet sense 1 (containing aphorisms or maxims):
aphoristic
WordNet sense 2 (of or relating to or derived from axioms):
axiomatical, postulational
WordNet sense 3 (evident without proof or argument):
self-evident
WordNet sense 4 (easily perceived by the senses or grasped by the mind):
obvious
From the ODE community, based on WordNet
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