πεντακυμία
From LSJ
καὶ λέγων ὅτι Πεπλήρωται ὁ καιρὸς καὶ ἤγγικεν ἡ βασιλεία τοῦ θεοῦ· μετανοεῖτε καὶ πιστεύετε ἐν τῷ εὐαγγελίῳ → declaring “The time has been accomplished and the kingdom of God is near: start repenting and believing in the gospel!” (Μark 1:15)
English (LSJ)
ἡ,
A fifth wave, supposed to be larger than the four preceding, Luc.Merc.Cond.2 ; cf. τρικυμία.