(Greek: covered, cover; hide, hidden; conceal, concealed)

(Latin: to hide; hidden; secret)

(Greek: kryptos, "hidden"; gas)

(Modern Latin: chemical element; from Greek, lanthanein, "hidden", "to be concealed"; rare earth)

(Latin: secret, secrecy; hidden, concealed, private)

(Greek: hidden, secret, secrets, secret writing; by extension, applied to secret code or ciphers)

(Latin: secret, hidden, concealed)

(Latin: to lurk; to lie hidden, to be hidden)

(Greek > Latin: lie hidden, secret; forgetfulness, forget, inactive through forgetfulness; also sleepy, drowsy, dull, sluggish)

(a secretly hidden coding that dates back to ancient Greece and is used even in this modern era)

(Greek: covering, covered, to cover; roof; by extension, secret, secret writing, applied to a secret code, codes, or ciphers that are hidden)