stu·pid·i·ty (sto͞o-pĭd′ĭ-tē, styo͞o-) n. pl. stu·pid·i·ties 1. The quality or condition of being stupid. 2. A stupid act, remark, or idea. stupidity (stjuːˈpɪdɪtɪ) n, pl -ties 1. the quality or state of being stupid 2. a stupid act, remark, etc stu•pid•i•ty (stuˈpɪd ɪ ti, styu-) n., pl. -ties. 1. the state, quality, or fact ...