竹 is a bound morpheme (不成词语素) meaning 'bamboo'. It rarely stands alone in modern Chinese; instead it appears as the first element in compound words like 竹子 (bamboo plant), 竹林 (bamboo grove), 竹竿 (bamboo pole), and 竹制 (made of bamboo). As a learner, you will encounter it mostly in these compounds rather than as an independent word.