Usage of "plurality"

Factual Questions
1

I’m writing a few sentences containing this infomation:
There are 39 senators of party X.
There are 80 total senators.
There are three different parties and party X is the largest.

Now, party X doesn’t have a majority of the vote, but do they have a plurality of the vote? Are they the majority party? Is their party a plurality? Is it interchangable in this instance?

I don’t want to misuse these words. Thanks.

2

I believe the term 'plurality" is usually used in regards to elections with three or more candidates. The candidate with the most votes has a plurality but not necessarily a majority.

I think it would be a perfectly acceptable usage, though, to apply it as you have indicated, meaning more than the others, but less than half.

3

Thanks Diogenes.