By and large, the project was a success despite some minor issues.

by 在这里是介词，表示"通过某种方式"或"根据某种标准"。 and 是连词，用于连接两个词或短语。 large 是形容词，意思是"大的"或"广泛的"。 by and large 是一个固定短语，意思是"总的来说"或"大体上"，表示从整体上看待事物。