an understanding of the causes or basis of a problem. (*Typically: determine ~; figure out ~; find ~; get to ~; get at ~.) It will take a little more study to get to the root of the problem. Let's stop avoiding the issue and get at the root of the problem.
Firmly resolved to, as in He was bound and determined to finish the assignment before taking on another. This phrase is a redundancy used for emphasis, as bound and determined here both mean "resolved to." Also see bound to.