There's No Such Thing as a Weed
Anyone who knows me knows I'm a huge fan of ethical foraging during our short but sweet growing season in Alberta. Our ditches and crown lands are filled with beautiful prairie flowers like clover, chamomile, mustard, and tansy. They grow in abundance and with vigour, and to their detriment, are then commonly mislabeled as weeds by the public.
Cue my eye twitch and me reaching for a soapbox to spread the good word.

Because here's the thing - the term 'weed' was created with the intention of identifying any unwanted plant. So, if you purchase a home and the previous owner had decided to line your property with peonies, roses, and dahlias, and you happened to be one of the rare few who hated all three (wut wrong wit you?) - they'd all be considered weeds!
In fact, the original definition of the word was written as "A plant not valued for its use or beauty."
Meanwhile...
Red Clover can be used to treat inflammation, skin disorders, and respiratory issues.
White Clover can be used as an antiseptic and analgesic (to clean wounds and numb pain and shit).
Sweet Clover is a natural air freshener and can be used to combat fluid retention as well as relieve symptoms stemming from poor blood circulation.
Chamomile, one of the most common and oldest tea ingredients, has been used to treat everything from anxiety, insomnia, and menstruation symptoms to hay fever.
Wild Mustard greens can be used for salads while the seeds can be harvested and used as a spice or to grow sprouts from.
And Tansies not only kill lice and bacteria, but are packed with antioxidants and can be useful in treating colds, fevers, kidney problems, and even gout.

So while we may have our disagreements about each one's beauty, there is no doubt that these plants all carry valuable properties and are intentionally grown by some for those properties. Why, then, the label? There is no one source I've been able to track down, but many believe the term was coined for farmers and gardeners to have a common language to discuss their problems through. Used in this context, it absolutely is correct to refer to anything that unexpectedly pops up and uses nutrients in your farm, garden, or landscaping as a weed.