This is the 149th most frequent Thai word.
ขอนแก
The word "ขอนแก่น" (Khon Kaen) refers to a province in northeastern Thailand.
Here, 'แก้' is used as 'adjust' or 'correct' and refers to modifying something for improvement or accuracy.
ฉันต้องการแก้ไขแผนที่นี้ก่อนเดินทาง
I need to adjust this map before the trip.
Here, 'ขอนแก่น' is used as a place name, Khon Kaen, a province in Thailand.
ฉันจะเดินทางไปขอนแก่นพรุ่งนี้
I will travel to Khon Kaen tomorrow.
In this sentence, 'ขอแก้' means 'ask for solving' or 'request to solve', with 'ขอ' as 'request' and 'แก้' as 'solve' or 'fix'.