preamble
/priːˈæmbl/noun
1- a preliminary or preparatory statement; an introduction开场白; 导言：
he could tell that what she said was by way of a preamble
他听得出她所讲的只是个开场白
mass noun I gave him the bad news without preamble.我径直把坏消息告诉了他。
1.1
- Law the introductory part of a statute or deed, stating its purpose, aims, and justification【律】（法规, 契约的）序言, 导言, 序文。
派生词
preambular
adjective （〈正式〉）词源
late Middle English: from Old French preambule, from medieval Latin praeambulum, from late Latin praeambulus 'going before'.