noun
best friend
A direct loan from English, used in casual contexts to refer to one's closest friend. Often used by younger speakers.
彼女は私のベストフレンドです。
She is my best friend.
ベストフレンドと一緒に旅行に行った。
I went on a trip with my best friend.
Variant with interpunct; less common but seen in some contexts.
Loanword from English 'best friend'.