plain, clear, distinct, certain, easy to understand, comprehensible, understandable, obvious, open, visible, easy to see, easily seen, manifest, self-evident, unmistakable, unequivocal, plain as the nose on one's face*, clear as crystal*, plain as day*.
Antonyms obscure*, vague, uncertain.
"self-explanatory." YourDictionary, n.d. Web. 06 June 2018. <http://thesaurus.yourdictionary.com/self-explanatory>.
self-explanatory. (n.d.). Retrieved June 06th, 2018, from http://thesaurus.yourdictionary.com/self-explanatory