Facebook gardening groups post pictures of plants found in their yards and ask "Is this a plant or a weed?" Botanically that is a terrible statement because all weeds are plants, though not all plants are weeds. But what the writer meant was, "Is this a desirable or undesirable plant?"
We can identify the plant, and if the property owner didn't plant it, then it will likely be called a weed.
But that is so limited! I'd like at least a third category.