buddy 哥们儿；BFF（best friends forever）闺蜜；confidante 红颜知己；colleague 同事；intimate 至交；sworn brother 结拜兄弟；partner 搭档；companion 同伴；pen pal 笔友；comrade-in-arms 战友；bosom friend 知心朋友；childhood sweetheart 青梅竹马