Dictionary entry

τέρας

G. Abbott-Smith's A Manual Greek Lexicon of the New Testament

τέρας, -ατος, τό

[in LXX chiefly for מוֹפֵת;]

a wonder, marvel: in NT always pl., τ. κ. σημεῖα, Mt 24:24, al. (v.s. σημεῖον)