Mary moved to her aunt's house, an inn, but she had got married to a strange, powerfully-built man.

powerfully 是由名词 power（力量）加上后缀 -ful（充满...的）变成形容词 powerful（强有力的），再加上后缀 -ly 变成副词形式。 powerfully-built 是由副词 powerfully 和过去分词 built（建造、构成）组成的复合形容词，字面意思是"以强有力的方式构建的"，用来形容"体格健壮、身材魁梧"的人。