Noun
いんぼう
彼は秘密結社が世界を支配しているという陰謀論を信じています。
He believes in a conspiracy theory that a secret society is controlling the world.
Under the shade people conspire. When people do this, conspiracy appears.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.