n.(Middle Ages) a person who is bound to the land and owned by the feudal lord
同义词：helotvillein
英汉双解大词典
serf/sɜːf/TEM8(serfs)
1.
N-COUNT（可数名词）
In former times, serfs were a class of people who had to work on a particular person's land and could not leave without that person's permission. 农奴