au courant
/əʊkʊˈrɒŋ/adjective
1- aware of what is going on; well informed熟悉现状的; 消息灵通的：
they were au courant with the literary scene.
他们很熟悉时下的文学状况。
1.1
- fashionable时髦的; 流行的：
light, low-fat, au courant recipes.
流行的清淡低脂食谱。
词源
mid 18th cent.: from French， literally 'in the (regular) course'.