Predestined is a word that has been widely debated for many centuries, particular when it comes to arguments over determinism and free will, as the definitions of predestined and predetermined are closely related but do have distinct differences.
To predestine means to ordain or decree something beforehand, especially in a divine or theological context. It specifically refers to the belief that God has determined the end of something, or the destination of a particular people group, but not determining the things led to that end.
For example, God says in Eph 1:5, that believers are predestined to adoption. The adoption is predestined, destined beforehand, that before believers believed, God had determined that anyone in Christ would be adopted as we enter into the presence of God. This is a different idea to being determined by God to do all the things in the process for an individual to be adopted.
On the determinism/free will spectrum, Scripture seems to sit somewhere between both ends. They speak as if God neither fully determines all things, nor is humanity able to do anything that it wants because of its lack of capacity to effect all the things that the mind of man can imagine