After losing his wife, the old man became a recluse and barely spoke to his neighbors.

recluse 是名词，来自拉丁语 recludere（关闭、隔离）。前缀 re- 表示"回、重新"，词根 cludere 表示"关闭"。recluse 指"隐居者、遁世者"，形容一个人主动远离社会交往，过着与世隔绝的生活。