The word for today is…
recondite (adj) – 1. Not easily understood; abstruse or obscure.
2. Concealed; hidden.
Source : The Free Dictionary
Etymology : While the adjective recondite may be used to describe something difficult to understand, there is nothing recondite about the word’s history. It dates to the early 1600s, when it was coined from the synonymous Latin word reconditus. Recondite is one of those underused but useful words that’s always a boon to one’s vocabulary, but take off the re- and you get something very obscure: condite is an obsolete verb meaning both “to pickle or preserve” and “to embalm.” If we add the prefix in- to condite we get incondite , which means “badly put together,” as in “incondite prose.” All three words have Latin condere at their root; that verb is translated variously as “to put or bring together,” “to put up, store,” and “to conceal.”