adjective
[more ~; most ~]
not well-known :not known to most people
difficult to understand :likely to be understood by only a few people
difficult or impossible to know completely and with certainty
synonyms obscure, vague, and ambiguous mean not clearly understandable. obscure often suggests a meaning that cannot be easily understood because it has not been clearly expressed or because special knowledge is needed.
verb
-scures; -scured; -scuring
[+ obj] to make (something) difficult to understand or know :to make (something) obscure
to hide or cover (something) :to be in front of (something) so that it cannot be seen