purple border（紫边）是什么意思？音标发音+图解场景

紫边 /ˈpɜːpəl ˈbɔːdə/ n

English: purple border · 紫边

释义：In ancient Rome, the purple border was worn by magistrates and by boys until the age of 16.

这个词出现在以下图解场景（1）