IPA: /dɪˈfɛnsɪvnəs/
KK: /dɪˈfɛnsɪvnəs/
The quality or state of being protective or anxious about criticism, often leading to a defensive attitude.
Her defensiveness made it difficult for her to accept feedback from her colleagues.
Defensiveness is formed from "defens-" (from Latin "defendere", meaning to ward off or protect) and "-iveness" (a suffix indicating a state or quality). The word describes the quality or state of being defensive, or the tendency to protect oneself from criticism or attack.
Think of 'defending' ('defens-') yourself, which leads to the quality of being defensive.