My son’s school uses the word “incursion” for events held within a school, as opposed to “excursions” where children leave the school for a field trip to learn something.
For me an incursion is a military raid or a hostile attack.
ISTM (without first, you know, looking it up), an incursion means someone or something from outside coming in (with the implication of being uninvited or unwanted). The military meaning mentioned above may be the most typical usage. But it can also mean something like an incursion of salt-water into a fresh-water marsh, or an incursion of Ebola virus into the United States – anything like that.
Whereas excursion means someone or something from inside going out. The usual meaning is a field trip of some sort, which lacks the “uninvited or unwanted” connotation. When the Apostles fanned out across Asia Minor, that was an excursion. When Dick Cheney broke Republican orthodoxy and spoke of allowing gay marriage ( ! Can you believe that? I just saw it mentioned in a news article today! ), that was an excursion.
When a bunch of school kiddies have some event where they stay right there at the school, I can’t see that as in incursion. Maybe it’s an intra-cursion.
It’s just a cursion.
And these people are teaching your children.
I am so sorry.
When you take a field trip inside of another field trip, would that be a recursion?
Hm… an event inside a school where the children learn something… how about “school”?
It’s certainly not an incursion.
This usage finds little favor with those who provide normal definitions of the term, which typically run along the lines of:
- a hostile entrance into or invasion of a place or territory, especially a sudden one; raid: “The bandits made brief incursions on the village.”
- a harmful inroad.
- a running in: “the incursion of sea water”.
Yeah, incursion means to invade or intrude, something coming in. Judging by the dictionary listings, they all seem to be negative. If someone came to the school to give a talk, you still wouldn’t call it an incursion. Maybe they should call it a “staycursion,” like “staycation,” which is when you take a vacation and stay at home. Making up a stupid word is no worse than using a completely wrong real word, is it?
That’s Inception.
I like this use of incursion.
Perhaps I will invite my closest friends over for an incursion into my home soon.
Invite a SWAT team. They’ll be able to do it better. 
What’s wrong with calling it an “Event?”
“Insurgency” would be cooler, though.
When I was in school, we called that Assembly.
When I called out to assembly, I used the ABI’s calling conventions.
So call it a convention.