1. To lean against or angle into something. He slanted against the doorframe with his eyes narrowed and his arms crossed while I packed my things into a suitcase. The fence has gotten so weighed down with ivy that it has started slanting against the side of the house.

2. To hold, represent, or play into a bias against someone or something. While the newspaper typically slants against the politician, it has come out in favor of her new tax reform proposal. The group has always slanted against any form of governmental control or interference, promoting deregulation and state-level autonomy instead.

3. To write or present something in such a way as to form, represent, or play into a bias against someone or something. In this usage, a noun or pronoun is used between "slant" and "against." Please try to keep your writing neutral—we don't want you slanting your articles against any politicians or political parties. Purporting itself to simply be presenting facts, it's pretty clear the director has slanted the documentary against the criminal justice system.