Verses with the word secretly in the New Testament (2 verses):

John 11:28
And when she had so said, she went her way, and called Mary her sister secretly, saying, The Master is come, and calleth for thee.

John 19:38
And after this Joseph of Arimathaea, being a disciple of Jesus, but secretly for fear of the Jews, besought Pilate that he might take away the body of Jesus: and Pilate gave him leave. He came therefore, and took the body of Jesus.