There are a lot of simple definitions out there, but I think there is no perfect wording that you can craft to convince them of the validity of peoples’ experiences. You will know pretty much right away where they’re at. People who are open and willing to be respectful will be curious, interested, and maybe kind of awkward or misinformed at first but you’ll see the good faith and see their attempt to understand and be kind about it - whereas people who have no intention of understanding will often pretend it’s much way confusing than it is (it’s not!), or get hung up on grammar, focus on semantics or how they’re “too old”, etc. Explaining the concept itself pretty easy, but the hard part comes if they’re not really listening. But, hopefully “oh, so that’s what that means! Huh! Your cousin three times removed was sorta like that, let me tell you a story…” will be the response you get.