隠密[onmitsu] privacy
過密[kamitsu] overcrowding
確率密度関数[kakuritsumitsudokansuu] probability density function
機密[kimitsu] secrecy
機密性[kimitsusei] confidentiality

機密保護[kimitsuhogo] security (e.g. data, password, etc.)
気密[kimitsu] airtight
気密室[kimitsushitsu] airtight chamber
緊密[kinmitsu] rigour
軍事秘密[gunjihimitsu] military secret

隠しカメラ[kakushikamera] hidden camera
隠し引き出し[kakushihikidashi] secret withdrawal
隠し芸[kakushigei] hidden talent
隠し撮り[kakushidori] taking pictures secretly
隠し子[kakushigo] illegitimate child

隠し事[kakushigoto] secret
隠し場所[kakushibasho] cache
隠し食い[kakushigui] eating on the sly
隠し立て[kakushidate] secrecy
隠くす[kakusu] to hide