Situationships aren't undefined. They're defined by whoever benefits
The word suggests confusion. In practice these arrangements are usually very clear to one person and deliberately vague to the other.

The framing everyone uses is that a situationship is a relationship without a definition. That framing is comfortable and mostly wrong.
Undefined implies mutual confusion — two people equally unsure, both waiting for clarity to arrive on its own. That happens, but it's rare. The far more common shape is one person who knows exactly what this is and is content with it, and one person who doesn't and isn't.
The tell is simple: whichever of you is searching for a quiz about it is the one for whom this is unresolved.
Three things that actually define it
Forget the label and check three concrete things.
Clarity. Has anyone said what this is, out loud, in words? Not implied it. Said it. Most people overestimate this badly — you can have months of behavior that looks like a relationship and zero sentences that make it one.
Effort. Who reaches out, who plans, who follows up? Not once. On average, over a month. If you already know the answer without doing any counting, that answer is lopsided and you've been aware of it for a while.
The future. Does anything exist on the calendar past this week? Not a wedding — a concert in six weeks, a trip in spring, anything with a date. The presence or absence of a future is the single most honest signal in the whole arrangement, because it's the one thing neither person can fake.
Those three, combined, produce eight quite different situations. Only one of them is the classic version.
Why they persist
An undefined arrangement continues because it costs one person nothing.
No definition to maintain, no calendar, no obligations, no conversations about where this is going. Things that cost nothing tend to run indefinitely — not out of malice, usually, but out of the same inertia that keeps anyone in a comfortable arrangement they haven't examined.
Meanwhile it costs the other person a lot: attention, planning, hope, and the specific fatigue of managing your own expectations on a daily basis. That asymmetry is the engine. It's why waiting rarely works. Nothing about the situation applies pressure to the person who'd need to change it.
The conversation is shorter than the wait
People avoid defining it because they think the conversation will end it. Occasionally that's true. Much more often what happens is one of two things: the other person says yes, they'd been waiting for the same reason and were equally scared — or they give a vague answer.
A vague answer is an answer. That's the part worth internalizing. "I don't really want to label things" delivered warmly is a complete response, and treating it as an unfinished one is how people lose another eight months.
The whole exercise fits in one sentence: I think this is something, and I'd like to call it that. Then stop talking and let the silence do its work.
If you already know
Plenty of people take a quiz to confirm what they could have said out loud on day one. That impulse is worth respecting rather than mocking — external confirmation makes a thing feel real enough to act on, and sometimes that's the piece that's missing.
But if you're there: you don't need more information. You need to decide what this would have to become to be worth it, say that once, and then watch what actually happens.
What happens next is the answer. It always was.