Intelligible
Part of speech: adjective
Definition: capable of being understood; clear to the mind
Example sentence: We see that pedantry has never been held in such esteem for the government of the world as in our times, and it offers as many paths of the true intelligible species and objects of infallible and sole truth as there are individual pedants.
Understandable
Part of speech: adjective
Definition: Capable of being understood; comprehensibleCapable of being accepted or excused under the circumstances
Example sentence: Gravitation is, so far, not understandable in terms of other phenomena.