Free will is a pair of dangling references: free from what? Will of who? Predetermined is a pair of dangling references too: pre, before what? determined by whom?
I like this definition by Klemm:
Analysis of the controversy requires clear definitions of a few terms, which unfortunately are often used colloquially with poor precision. To a degree, such problems are inevitable. Nonetheless, operational definitions are helpful. Free will could be defined in various ways. Will is herein operationally defined here by such synonyms as intent, choice, or decision, and it can be accomplished consciously or subconsciously. Free implies a conscious causation in which an intent, choice, or decision is made among alternatives that are more or less possible of accomplishment and are not constrained by either external or internal imperatives for the embodied brain.
Free will debates: Simple experiments are not so simple
I think the core of issue is that the determinism does not imply that everything is 'predetermined' or 'predeterminable'.
Gisin has argued that there is, in fact, no conflict between predetermined properties (realism) and an open future:
Realistic true randomness is some sort of nondeterministic force, or propensity of physical systems to manifest such and such properties under such and such conditions. Realistic random events reflect preexisting properties, as required by realism, simply the reflection is not deterministic; still, the preexisting properties determine the propensities of the different possible events.
Is realism compatible with true randomness?