He was born in the countryside, more precisely in Bourgogne, and he had always lived there.

precisely 是形容词 precise 的副词形式，precise 意思是"精确的、准确的"，加上 -ly 变成副词后表示"精确地、准确地"。在这里用来强调说话内容的准确性，相当于汉语的"确切地说"。