to bend something out of its straight shape, and so to twist a verdict, a scale, or a person's rightful claim
The picture behind this verb is physical. Something straight gets bent, and a bent thing does not go back on its own. Ecclesiastes uses it that plainly, of what is crooked and cannot be straightened, and of strong men stooping in old age. Everywhere else the Bible takes that picture and applies it to conduct, and what gets bent is always something that was supposed to stay straight: a court ruling, a merchant's balance, a person's rightful claim.
That is why the word keeps turning up in arguments about God's fairness. Job's friend Bildad asks whether God bends a verdict, expecting the answer no. Elihu says flatly that the Almighty never does. Job, using the very same verb, charges that God has bent his own case. Amos overhears merchants planning to bend their scales so the weights will lie. In each place the wrong is named by its shape: not so much a rule broken as a straight thing pulled out of line.
The verb does not always accuse. Psalm 146 says the LORD bends the road of the wicked, which is his justice at work rather than an offense, and Ecclesiastes uses it for the plain crookedness of things that nobody can correct. Hebrew has a close relative that runs the other direction, describing a person who bends himself into guilt (עָוָה); this verb almost always has an object outside the one doing the bending.