<p>As a passive control technique, vibration absorption typically requires a certain mass to achieve effective energy transfer and dissipation, which limits its application in lightweight structures. To address this challenge, a novel nonlinear vibration absorber is proposed that exploits translation-rotation coupling to achieve low-frequency vibration absorption while maintaining a low added mass. The dynamic equations of the system are derived using Lagrange's equations, and the nonlinear characteristics are analyzed both analytically and numerically. The frequency-response near equilibrium is obtained via the harmonic balance method, confirming the softening nonlinearity of the absorber. Numerical simulations based on a two-story host structure are conducted to analyze the response under different excitation levels, and its vibration absorption performance is verified. Comparative studies confirm that, for the same auxiliary mass, the proposed absorber achieves superior mitigation and robustness compared with a conventional tuned mass damper. Parameter optimization via the genetic algorithm further enhances performance and ensures robustness across various excitations. These findings highlight the potential of inertia-amplified nonlinear absorbers as a lightweight and reliable solution for pulse mitigation in engineering structures.</p>