expletive

脏话、咒骂语、粗话正式

He muttered an expletive when the coffee spilled on his shirt.

咖啡泼到衬衫上时，他低声骂了一句脏话。

虚词、赘词语言学

In this sentence, the word "there" functions as an expletive.

在这个句子里，there 这个字是虚词。

填补的、赘余的语言学

Grammarians call this an expletive use of the pronoun.

语法学家称这是该代名词的填补用法。