He was a farmer who had been working in the fields for more than sixty years, but was still alive and kicking.

alive 的意思是"活着的"，指生命状态。 and 是连词，表示并列关系，连接两个状态或动作。 kicking 是动词 kick 的现在分词形式，kick 本意是"踢"，这里用作比喻意义表示"活跃"。 alive and kicking 是一个固定短语，字面意思是"活着并且还能踢"，引申为"精神饱满、充满活力"的意思。