Defensive astuteness refers to the ability to effectively defend oneself from potential threats or attacks. Synonyms for this concept might include defensive agility, protective savvy, or guarded sharpness. Another possible synonym is self-defensive shrewdness, which highlights the idea that defensive astuteness involves being smart and strategic about defending oneself. Other synonyms might include defensive acuity, guarded perspicacity, or protective discernment. Ultimately, the concept of defensive astuteness implies a certain level of awareness and readiness to protect oneself in potentially risky situations, and any synonymous terms should reflect this idea of adaptive defense.