during one's stay; while staying
Used to describe something that happens or is true while someone is staying at a place, often in travel or business contexts.
滞在中は、毎日観光に出かけました。
During my stay, I went sightseeing every day.
滞在中のホテルで無料Wi-Fiが使えます。
You can use free Wi-Fi at the hotel during your stay.
While staying in Kyoto, I visited many temples.
It rained the whole time I was staying there.
During my friend's stay, I took them to a nearby hot spring.
Compound of 滞在 (stay) + 中 (during, in the middle of).