In Acts 2:23 we read: τοῦτον τῇ ὡρισμένῃ βουλῇ καὶ προγνώσει τοῦ θεοῦ ἔκδοτον διὰ χειρὸς ἀνόμων προσπήξαντες ἀνείλατε.
προγνώσει seems to be fairly consistently translated as 'foreknowledge' but there seems to be difference of opinion in regards to what exactly is meant by 'foreknowledge', for example Louw Nida has this entry
28.6 προγινώσκωa; πρόγνωσιςa, εως f; προοράωb: to know about something prior to some >temporal reference point, for example, to know about an event before it happens—‘to know beforehand, to know already, to have foreknowledge.’ προγινώσκωa: προγινώσκοντές με ἄνωθεν, ἐὰν θέλωσι μαρτυρεῖν ‘they have already known me beforehand, if they are willing to testify’ Ac 26:5; προεγνωσμένου μὲν πρὸ καταβολῆς κόσμου ‘known already before the world was made’ 1 Pe 1:20. It is also possible to understand προγινώσκω in 1 Pe 1:20 as meaning ‘chosen beforehand’ (see 30.100). πρόγνωσιςa: τοῦτον τῇ ὡρισμένῃ βουλῇ καὶ προγνώσει τοῦ θεοῦ ἔκδοτον ‘God, in his own will and foreknowledge, had already decided that this one would be handed over to (you)’ Ac 2:23. προοράωb: προϊδὼν ἐλάλησεν περὶ τῆς ἀναστάσεως τοῦ Χριστοῦ ‘knowing ahead of time, he spoke about the resurrection of the Christ’ Ac 2:31.4
That seems to suggest that foreknowledge is merely knowing before hand what will take place however some seem to place far more significance in the term then this, see for example L. Berkhof, Systematic Theology [Grand Rapids: Eerdmans, 1976], 112):
Proginoskein and prognōsis in the New Testament … do not denote simple intellectual foresight or prescience, the mere taking knowledge of something beforehand, but rather a selective knowledge which regards one with favor and makes one an object of love, and thus approaches the idea of foreordination, Acts 2:23 (Comp. 4:28); Rom. 8:29; 11:2; 1 Peter 1:2. These passages simply lose their meaning, if the words be taken in the sense of simply taking knowledge of one in advance, for God foreknows all men in that sense. Even Arminians feel constrained to give the words a more determinative meaning, namely, to foreknow one with absolute assurance in a certain state or condition. This includes the absolute certainty of that future state, and for that very reason comes very close to the idea of predestination.
We all know that just because a word breaks down into two or more others words it does not mean that the word's meaning is a compound meaning of the words it can be broken down into - for example, buttercup does not refer to a cup of butter but to a yellow flower. However Greek is a more 'synthetic' language then English and words often reflect the meaning of their component parts in Greek.
So what does πρόγνωσις mean in the context of Acts 2:23 and how would you translate this verse to clear up the apparent ambiguity of meaning?