also: ほうえ
noun, noun which may take the genitive case particle 'no'
vestment; priest's robe
Specifically refers to the robe worn by Buddhist priests. The reading ほうい is standard; ほうえ is also used.
僧侶が法衣をまとって読経を始めた。
The monk put on his vestment and began chanting sutras.
袈裟 is a specific type of Buddhist robe (a surplice), while 法衣 is a broader term for priestly vestments.
From Middle Chinese 法衣 (pjuwop ʔjɨj), literally 'dharma garment'. The reading ほうい is the regular Sino-Japanese reading; ほうえ is an older or dialectal variant.