示 is a bound form (不成词语素) meaning 'show, indicate, demonstrate'. It rarely appears alone in modern Chinese; instead, it combines with other morphemes to form common verbs and nouns like 表示 (express), 指示 (indicate/directive), and 出示 (produce/show ID). When you see 示 at the head of a compound, it usually carries the sense of 'displaying or making known'.