Sense

1. (of place) backwards
2. back, back again, by the same way one took
3. again
4. (with genitive) after

Examples

• καὶ ἀπέστειλε τὴν περιστερὰν ὀπίσω αὐτοῦ ἰδεῖν, εἰ κεκόπακε τὸ ὕδωρ ἀπὸ τῆς γῆς. (Septuagint, Liber Genesis 8:8)
• ἀκούσας δὲ Ἅβραμ ὅτι ᾐχμαλώτευται Λὼτ ὁ ἀδελφιδοῦς αὐτοῦ, ἠρίθμησε τοὺς ἰδίους οἰκογενεῖς αὐτοῦ, τριακοσίους δέκα καὶ ὀκτώ, καὶ κατεδίωξεν ὀπίσω αὐτῶν ἕως Δάν. (Septuagint, Liber Genesis 14:14)
• ἐξῆλθε δὲ Λὼτ πρὸς αὐτοὺς πρὸς τὸ πρόθυρον, τὴν δὲ θύραν προσέῳξεν ὀπίσω αὐτοῦ. (Septuagint, Liber Genesis 19:6)
• καὶ ἐγένετο, ἡνίκα ἐξήγαγον αὐτοὺς ἔξω καὶ εἶπαν. σῴζων σῷζε τὴν σεαυτοῦ ψυχήν. μὴ περιβλέψῃ εἰς τὰ ὀπίσω, μηδὲ στῇς ἐν πάσῃ τῇ περιχώρῳ. εἰς τὸ ὄρος σῴζου, μήποτε συμπαραληφθῇς. (Septuagint, Liber Genesis 19:17)
• καὶ ἐπέβλεψεν ἡ γυνὴ αὐτοῦ εἰς τὰ ὀπίσω καὶ ἐγένετο στήλη ἁλός. (Septuagint, Liber Genesis 19:26)

Source: Ancient Greek entries from Wiktionary