～泊
～はく · ～haku · JLPT N2 · noun
gram
🛏️🏨 泊 = water 氵 + 白: a boat anchored at the shore for the night
泊 first meant mooring a boat for the night, so it came to mean any overnight stay. As a counter it counts nights: 一泊 (ippaku) is one night, 二泊 (nihaku) is two. Hotel booking sites use it all the time.