Privily

Vine's Expository Dictionary of NT Words

1: Λάθρᾳ (Strong'S #2977 — Adverb — lathra — lath'-rah )

"secretly, covertly" (from a root lath---, indicating "unnoticed, unknown," seen in lanthano, "to escape notice," lethe, "forgetfulness"), is translated "privily" in  Matthew 1:19;  2:7;  Acts 16:37; "secretly" in  John 11:28 (in some mss.,   Mark 5:33 ). See Secretly.

 Galatians 2:4Come Jude 1:4Creep

King James Dictionary

PRIV'ILY, adv. from privy. Privately secretly.

--False teachers among you, who shall privily bring in damnable heresies.  2 Peter 2

Webster's Dictionary

(adv.) In a privy manner; privately; secretly.