A copse is a small group of trees or bushes growing close together — bigger than a few scattered trees, smaller than a forest. You walk into one and the light changes. It is a quiet, slightly old-fashioned countryside word, more at home in British English than in American speech, where people often say grove or thicket instead. Though actually, the history is more specific than the way we use it now: a copse (from coppice) first meant a little wood grown so people could cut it, wait for it to grow back, and cut it again. Today almost nobody is thinking about that when they say it. It is just a close stand of trees. You will meet it in stories, walking guides, and place names more than in city talk.