Which of the following best describes the act of bending the truth to deceive?

The term that best describes the act of bending the truth to deceive is "cozen." This word specifically refers to tricking or deceiving someone, often through misleading or clever means. It encompasses the idea of manipulating the truth to create a false impression, which aligns perfectly with the act of bending the truth.

The other choices do not convey this sense of deception as effectively. "Countenance" generally refers to someone's demeanor or facial expression and does not imply any form of deceit. "Defalcate" pertains to embezzlement or misappropriation of funds, which is a specific type of dishonesty but does not necessarily involve bending the truth itself. "Cavil" means to make petty or trivial objections, which is about arguing or raising minor concerns rather than actively deceiving someone. Thus, "cozen" is the most appropriate choice, as it directly relates to the act of deceit through distortion of the truth.