Recently found a question "modified 17m ago Community♦ 1".
I can't understand how Community♦ modified it - he didn't edit it, nor its answers.
He didn't poke it, if did, it would be written "poked" instead of "modified", isn't it?
So what does "modified" mean?
It was bumped by automatic process so that it has another chance to get attention, since it's not considered "answered" yet. (0 scored, non accepted answer is probably not good enough)
The Community user will bump non-negatively scored questions that have at least one answer scoring 0 and none scoring more than that. The number of unanswered questions bumped per hour depends on the site: 4 per hour on Stack Overflow, 1 per hour on Meta, and 2 per hour on Super User and Server Fault. The default for a new site is 1 per hour.
You are right that nothing was really modified in the question, this is an artificial change of the "last activity" timestamp of the question, but changing the wording isn't that important in my opinion.
Now that you know how it works, feel free to start new feature request asking to change "modified" to something else in case of auto bumping, but like I said, not sure it will be implemented.