知心女性朋友
She first was his colleague and then they got closer and closer and in the end she became his female bosom friend.───她只是他的同事，但后来两个人越来越亲密，最后她成了他的红颜知己。
bosom friend───知己；知心朋友；契友
bosom friends───知心朋友；密友；心腹之交
to make friends───交朋友
false friend───假朋友，不忠实的朋友
family friend───氏族朋友；家庭共同的朋友
gentleman friend───绅士朋友
loyal friend───忠实的朋友