If you're looking for a meeting place or a good stop around ½ or halfway between Fort Wayne and Defiance, you can try Jarrett Wood Subdivision, OH, which is about half an hour east of Fort Wayne, or about half an hour west of Defiance.
Another possible place to stop near the midpoint is Antwerp.
About ¼ or a fourth of the way, you can stop at New Haven, IN. This is about 12 minutes east of Fort Wayne.
About ⅓ or a third of the way, you can stop at Five Points, IN. This is about 17 minutes east of Fort Wayne.
About ⅔ or two thirds of the way, you can stop at New Rochester, OH. This is about half an hour east of Fort Wayne, or about 16 minutes west of Defiance.
About ¾ or three fourths of the way, you can stop at Cecil, OH. This is about half an hour east of Fort Wayne, or about 14 minutes west of Defiance.
If you drive straight through without stopping at all, the total distance is 52 miles. The distances shown above don't include local roads to get into each town, so if you're planning a long road trip, make sure you factor in traffic and road conditions, rest stop breaks, and interesting detours along the way. If you're in a rush, you can do the trip with zero stops, and your total travel time would be around 53 minutes.