na-adjective, noun
unenlightened; ignorant; uneducated
A formal, somewhat literary yojijukugo describing a state of profound ignorance or lack of enlightenment. Often used in critical or self-deprecating contexts.
彼は自分の無知蒙昧を恥じた。
He was ashamed of his own ignorance.
無知蒙昧な人ほど、自分の考えに固執する。
The more ignorant a person is, the more they cling to their own ideas.
A yojijukugo composed of 無知 (ignorance) and 蒙昧 (unenlightened, dark). The exact historical derivation is uncertain, but it is conventionally used to express profound ignorance.