她用了一个生僻难懂的词来解释这个概念，让大家都听懵了。

She used a ___sesquipedalian word to explain the concept, leaving everyone confused.

他喜欢在对话中用些深奥难懂的词，显得自己很有学问。

He enjoys using ___sesquipedalian words in conversations to sound more sophisticated.