noun
governor of Hokkaido
Refers specifically to the governor of Hokkaido Prefecture, which is designated as a 道 (dō) rather than a 県 (ken) or 府 (fu).
道知事は来月の選挙で選ばれる。
The governor of Hokkaido will be elected in next month's election.
県知事 is the governor of a standard prefecture (県), whereas 道知事 is the governor of Hokkaido, which has the special designation 道.
Compound of 道 (dō, 'Hokkaido') and 知事 (chiji, 'governor'). The term is straightforward and modern.