Sensitive  adj. 1 (often foll. By to) acutely susceptible to external stimuli or impressions; having sensibility. 2 easily offended or hurt. 3 (often foll. By to) (of an instrument etc.) Responsive to or recording slight changes. 4 (of photographic materials) responding (esp. Rapidly) to light. 5 (of a topic etc.) Requiring tactful treatment or secrecy.  sensitively adv. Sensitiveness n. Sensitivity n.