A.T. Robertson Commentary Luke 21:25

"And there shall be signs in sun and moon and stars; and upon the earth distress of nations, in perplexity for the roaring of the sea and the billows;" — Luke 21:25 (ASV)

Distress (συνοχη). From συνεχω. In the N.T. only here and 2 Corinthians 2:4. Anguish.

In perplexity (εν απορια). State of one who is απορος, who has lost his way (α privative and πορος). Here only in the N.T. though an old and common word.

For the roaring of the sea (ηχους θαλασσης). Our word echo (Latin echo) is this word ηχος, a reverberating sound. Sense of rumour in Lu 4:37.

Billows (σαλου). Old word σαλος for the swell of the sea. Here only in the N.T.