They must have gone here to find it:
www.merriam-webster.com slash dictionary slash proactive.

It lists a definition for the word. pro + reactive.

Language changes all the time and there is nothing we really can do about it. I have pet peeves, but what can I really do but speak and write as I see the language. Most people these day confuse affect and effect, so they punt and use impact. They have reversed the meaning of peruse from "to read thoroughly" to "scan over quickly". Nouns get verbed all the time. We now rearchitect a software system, rather than redesign it.

A redneck gets into Harvard on a diversity/scholarship.

On his first day, he walks up to an upperclassman and asks; "Exsuse me. Can you tell me where the admissions office is at?"

The older student appears shocked, and states condescendingly; "Young man, this is Harvard. You will soon learn that at this institution, we do not end our sentences with prepositions."

The redneck replies; "Sorry. Can you tell me where the admissions office is at, asshole."

One of my long-time teeth-gritters: "remediate."

Evolved, to my knowledge, from the environmental field (my first career). "EPA is requiring us to remediate the site." Or, "It will cost us $400,000 to remediate the contamination."

Remediation is a noun. The verb form is remedy. The adjective is remedial (i.e., "remedial action").

"EPA is requiring us to remedy the contamination at the site." There ya go!

Sadly, government agencies and courts have taken up use of "remediate."

...and several others...

I've always been intrigued by the words 'unrelenting' and 'relentless', to never give up, never surrender.

So in order to give myself a break from a potentially out-of-control type A personality, I have learned to 'relent', or give myself a break.

In order to achieve harmony with the universe, I am now trying to 'lent' myself more frequently. Which probably means 'to pursue.' As I stared at myself in the mirror one morning, I realized tThere's got to be a dog-in-the-grass, Alice in Wonderland through-the-looking-glass metaphor in there somewhere.

Alas, I have no desire to chase the 50-yr old flabby bald guy I saw on the other side...

To add to the Pointlessly Big Words collection: what's with "utilize"? I've never seen a sentence where utilize couldn't be replaced with use without affecting the meaning in the slightest.

"Nouns get verbed all the time."

"Verbed" being a prime example of it, and why it can be annoying. I think (to be specific: I'm pulling this out of my ass) that as you learn a language and build a vocabulary and a grammar, you assign different words their "proper" part of speech. So your natural sense of linguistic wrongness is going to tag it when a person uses a word in a sense that you learned is incorrect.

The thing is that language peeves are a natural part of your personal grammar.

Oh, and I think proactive is a perfectly good word. In my usage, pro- means "preventative or denying", as in proscription or proscribe, and active means "in the nature of an action." Proactive means that what you are doing is something to prevent or deny, and you're usually referring to preventing a future problem. So that's why it makes sense to me. Most people are just unfamiliar with the prefix pro-.

Irregardless. HUH!