What, exactly, constitutes an adventure? The definition may depend on whether you are inclined to seek out adventures or avoid them. On second thought, maybe whether you seek out adventures or avoid them depends on what kind of adventurous experiences you've had in the past—and how well they turned out.
According to one of my friends, an adventure is "going into the woods by a path no one else has used before."
According to another friend, it is "doing something really exciting and stupid, and living through it." (In some circles, this is prefaced by "Hold my beer and watch this!")
According to my father, an adventure is "something that, while it's happening, you wish you were home."
Not being the type to seek out excitement, I incline toward my father's definition. Adventures, for many people, involve excitement, exhilaration, thrills, and accomplishment. Most adventures also seem to involve being lost, under-equipped, overwhelmed, cold, wet, seriously uncomfortable, and stumbling around in the dark, sometimes metaphorically and more often literally. Oh, and did I mention being scared to death?
Regardless of the definition you use, though, and no matter whether you try to find adventure or try to keep it from finding you, there is one more component that is essential. An adventure is something that, after the fact, makes a good story.
After the peak has been scaled, the runaway horse has been stopped, the baby has been delivered, the hotel in the foreign city has been found, the bleeding has been stopped, or the fire has been put out—then comes the real test.
Some time after it's over, can you sit safely among a group of friends and tell them the story? With tears or shudders, perhaps, and with slight embellishments as appropriate, but always and most important, with laughter. That's what it takes to turn an experience into a genuine adventure.
Practical Prairie Woman 
Again, I enjoyed your article. I am not one to get into anything that I am not familiar with. When Ginny and I first started to take trips to foreign lands,I decided we would go to the British islands so we could understand the language, read the signs, and not get tangled up with problems that might arrise by not being able to communicate. My younger brother, Paul, on the other hand, is adventurous. He had worked in Zaire, Saudi Arabia, Japan and aboard those huge oilers. My wife says he is not so adventurous. He is just ignorant of catastrophy. Frank
You know you are getting old and live a quiet life when going to the grocery store is an adventure. Ginny
I love that phrase “ignorant of catastrophe.” It probably is responsible for a lot of unintended adventures!