indoors
UK: ɪnˈdɔːz | US: ɪnˈdɔːrz
adv. inside a building or enclosed space
adj. relating to or situated within a building
The word "indoors" combines "in" (Old English in, meaning "inside") and "door" (Old English duru, meaning "entryway"), with the adverbial suffix "-s" (a common Germanic adverbial marker). It literally means "within the doors," reflecting the concept of being inside a sheltered space. Over time, it evolved to broadly signify any interior environment, not just spaces behind literal doors.
It's raining heavily, so we should stay indoors.
The cat prefers to sleep indoors during winter.
Indoor plants thrive when placed near sunlight.
They moved the party indoors due to the storm.
Modern offices are designed to keep workers comfortable indoors.