I am sure I am not supposed to whinge when blogging but this itch needs scratching.
Far too often I hear, typically pedantic, technical folk explain the latest and greatest technology in the following way: "... and the wonder-widget can lead to a quantum leap in performance and scalability...". Do they really mean to say that the "wonder-widget" gives rise to the smallest measurable improvement in performance and scalability? Given the context of the pitch and fervour of the orator, I doubt it. How, when used as an adjective, did this come to mean a "significant" amount? Quantum mechanics is all about the small stuff.
The other one that really grates is "performant". Tweaking the threading and fiddling the concurrency will deliver the most performant system. It may deliver a high-performance system, or a highly-efficient system, or maybe even a well-performing system - just not a performant system. Performant means "a performer" as in "an actor".
Somehow these uses have forced themselves into mainstream use and the language will adapt and adopt them. Grrrr.