The actor does a lot of charity work offscreen, but it rarely gets media coverage.

offscreen 是由前缀 off-（表示"离开、不在"）和 screen（屏幕）组成的复合词，字面意思是"离开屏幕的"。在影视行业特指演员"不在镜头前/银幕外的"真实生活状态，与 onscreen（在镜头前）形成对比。