Other forms: downsides
The downside is the drawback of something otherwise good. The downside is the cost, on the downside, downside risk.
It concedes the good in the same breath, which is what makes it useful in an argument. In finance, downside risk is how much you could lose, as against upside, how much you could gain, and the pair is standard language for weighing a bet.
1noundownsideThe drawback of something otherwise good.
“The flat is lovely; the only downside is that it's on a noisy street.”
downside is a drawback.
Down plus side, a twentieth-century compound, largely American in origin.
Compound of down + side.
Etymology from Wiktionary, CC BY-SA