Prelusive is an adjective that means ‘introductory.’ 

The prefix P-R-E means before. If something is preslusive. If something is prelulusive it relates to a prelude or an introduction.

Here’s an example of prelusive in use:

The mayor’s prelusive statements suggested he’d be answering questions related to his current scandal. But his early remarks were the only time he addressed his recent troubles. Instead, he spent the hour extolling those in attendance to get out and vote for him in the next election.