noun, noun or participle which takes 'suru', intransitive verb
lodging; putting up at a hotel
Formal or written term for staying at an inn or hotel, often used in travel contexts. The する form is intransitive.
旅の途中、小さな宿に投宿した。
During the journey, I put up at a small inn.
投宿先はまだ決まって
The place to stay has not been decided yet.