Something that is worth for many different things. That has many different values or meanings.
A polyvalent object is one that can be used as many different things. A polyvalent emotion is one that you can show in many different situations and get favorable results.
From Ancient Greek "poly: many" and Latin "valens, valentis: that is worth it"
- What a polyvalent chair, you can use it as a chair to sit and as a table to put things on it.
A single person who dates a couple pretending to be interested in a manage a trois relationship, but who is there to divide and conquer , ending up with only one of the members of the couple.