Abbott-Smith Manual Greek Lexicon
νυστάζω (G3573)
2 νυστάζω (cf. νεύω ), [in LXX for נוּם , etc;] to nod in sleep , fall asleep : Mt 25:5 . Metaph., of negligence or delay, ἡ ἀπώλεια αὐτῶν οὐ νυστάζει (cf. Ps 120 (121):4 , Is 5:27 ): II Pe 2:3 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain