introductory
/ˌɪntrəˈdʌktərɪ/adjective
1- serving as an introduction to a subject or topic; basic or preliminary引导的, 引论的, 序言的; 基本的, 基础的, 初步的, 预备的：
an introductory course in Russian.
俄语基础教程。
1.1
- intended to persuade someone to purchase something for the first time说服…试购的, 试销的：
we are making a special introductory offer of a reduced subscription.
我们正在推出特惠价试订阅的活动。
词源
late Middle English (as a noun denoting an introductory text)： from late Latin introductorius, from Latin introducere （see INTRODUCE）.