Vine's Expository Dictionary: View Entry
λανθάνω lanthánō, lan-than'-o; a prolonged form of a primary verb, which is used only as an alternate in certain tenses; to lie hid (literally or figuratively); often used adverbially, unwittingly:—be hid, be ignorant of, unawares.
The KJV translates Strong's G2990 in the following manner: be hid (3x), be ignorant of (2x), unawares (1x).
to be hidden, to be hidden from one, secretly, unawares, without knowing
Strong's Number G2990 matches the Greek λανθάνω (lanthanō),
which occurs 6 times in 6 verses
in the TR Greek.
View OT results in the LXX Greek concordance
View NT results in the MGNT Greek concordance