eight faces; all sides
Literally 'eight faces', used to mean every direction or all sides. Often appears in set phrases like 八面六臂 (はちめんろっぴ, 'versatile, multi-talented') or 八面玲瓏 (はちめんれいろう, 'clear and beautiful from every angle').
He shows versatile activity in many fields.
その宝石は八面玲瓏の輝きを放つ。
The jewel shines with a clear beauty from every angle.
八方 means 'all directions' and is more common in everyday expressions like 八方美人 (a person who tries to please everyone). 八面 is more literary and often appears in four-character idioms.
Compound of 八 (eight) and 面 (face, surface). The number eight is used figuratively to mean 'many' or 'all', similar to 八方.