The meaning of “λάθρα”

“Then Joseph her husband, being a just man, and not willing to make her a publick example, was minded to put her away privily.”

“Then Herod, when he had privily called the wise men, enquired of them diligently what time the star appeared.”

“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.”

“But Paul said unto them, They have beaten us openly uncondemned, being Romans, and have cast us into prison; and now do they thrust us out privily? nay verily; but let them come themselves and fetch us out.”