秘事 is read as ひじ (hiji) and means secret.
ひじ
hiji
ひめごと
secret
ぐんじひみつ
military secret
ごくひじこう
closely-guarded secret
ひしょ
(private) secretary
ひみつ
esoteric teachings
ひめる
to hide
ひぞう
treasuring
ひわ
secret story
ひきょう
unexplored region
ひさく
secret plan
ひでん
secret (recipe, medicine, etc.)
ひとく
hiding