Abbott-Smith Manual Greek Lexicon
λανθάνω (G2990)
6 λανθάνω , [in LXX for עלם ni., etc.;] to escape notice , be hidden ( from ): Mk 7:24 , Lk 8:47 ; c. acc. pers., Ac 26:26 , II Pe 3:5 , 8 ; as in common cl. idiom, seq. ptcp., ἔλαθον ξενίσαντες , entertained unawares , He 13:2 (cf. ἐκ- , ἐπι-λανθάνω ).†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain