From BiblePortal Wikipedia

Hastings' Dictionary of the New Testament [1]

Rejection is an idea expressed by more than one word in the NT. (1) ἀποδοκιμάζειν, which means ‘to reject after trial,’ is used of our Lord in His own Person ( Mark 8:31,  Luke 9:22;  Luke 17:25), and of our Lord as ‘the stone which the builders rejected’ ( Matthew 21:42,  Mark 12:10,  Luke 20:17,  1 Peter 2:4;  1 Peter 2:7, in all these places quoted from Psalms 117 (118):22, although St. Luke, in reporting St. Peter’s words in  Acts 4:11, uses of the rejected stone ἐξονθενηθείς) and of Esau ( Hebrews 12:17); (2) ἀποβάλλειν (in the forms ἀπόβλητον,  1 Timothy 4:4, and ἀποβολὴ,  Acts 27:22,  Romans 11:15) and (3) ἀπωθεῖσθαι ( Acts 7:27;  Acts 7:39;  Acts 13:46,  Romans 11:1-2,  1 Timothy 1:19) are used in a general sense in most of the references.

In the references to Romans, (2) and (3) are employed in the special sense of the rejection of Israel to make way for the Gentiles as recipients of the gospel. It was a cause of deep distress ( Romans 9:2-3) to St. Paul that God’s chosen people whom He foreknew seemed to be rejected, and it was taken by opponents as a reflexion upon his apostleship that Israel as a nation rejected his gospel. But St. Paul did not admit the final rejection of Israel. ‘did God cast off his people (μὴ ἀπώσατο ὁ θεὸς τὸν λαὸν αὐτοῦ,  Romans 11:1)? God forbid.… God did not cast off his people which he foreknew.’ He then proceeds to show that Israel’s rejection is not final, and does not exclude individual members of the chosen race from the acceptance of gospel blessing. But Israel itself as a nation rejects the gospel ( Acts 13:46) in order that the offer of it may be made to the Gentiles, who had no hereditary claim to it and were not oven seeking it ( Romans 10:20).

The unbelief or disobedience of Israel is noted by St. Peter ( 1 Peter 2:8), who points out also, in language as strong as St. Paul’s, that Israel’s stumbling and rejection had a place in God’s great purpose in the salvation of men ‘whereunto they were appointed.’ This is a great mystery which St. Paul sets forth ( Romans 11:25), but in Gentile communities and under the conditions of Gentile life, the gospel had scope for world-wide extension and universal acceptance which were not possible among the Jewish people. Such, however, is the inherent genius of the Jewish people for religion that when they mark the blessedness and joy of Christian believers and the manifestations of grace in those who bear the name of Christ, they will be stirred up to seek as their own the righteousness and holiness manifested in the lives of Christians. ‘And so all Israel shall be saved’ and their election at the first upheld, seeing that the gifts and calling of God are incapable of being revoked ( Romans 11:25;  Romans 11:29). ‘did they stumble that they might fall?’ asks the Apostle. ‘God forbid: but by their fall salvation is come unto the Gentiles.… For if the casting away of them (ἡ ἀποβολὴ) is the reconciling of the world, what shall the receiving of them be, but life from the dead?’ ( Romans 11:11-15).

Thomas Nicol.

Webster's Dictionary [2]

(n.) Act of rejecting, or state of being rejected.