Meta tags have limited space, which means related-term usage here needs to be selective and purposeful rather than an attempt to cram in everything your research surfaced.
Prioritize the Single Most Relevant Related Term
With limited space, choose the related term that adds the most genuine value rather than trying to include several.
Let the Primary Keyword Remain the Clear Focus
Meta tags should still clearly communicate the page's main topic first, with any related term playing a clearly secondary, supporting role.
Avoid Meta Tags That Read as an Obvious Keyword List
A meta description stuffed with several related terms tends to read as unnatural and can undercut, rather than support, credibility.
Next step: Use the LSI Tool to identify the single most relevant related term worth including in a space-limited meta tag.