An ancient country in central Asia, corresponding to the northern part of modern Afghanistan. It was the seat of a powerful Indo-Greek kingdom in the 3rd and 2nd centuries BC.
巴克特里亚（中亚古国，相当于现代阿富汗北部，是公元前2-前3世纪一个强大的印度-希腊王国的所在地）
Definition of Bactria in US English:
Bactria
proper nounˈbaktrēə
An ancient country in central Asia, corresponding to the northern part of modern Afghanistan.