four-bedroom

The word is a modern English compound adjective formed by straightforwardly combining the cardinal number "four" with the noun "bedroom." The number "four" traces back to Proto-Germanic fedwōr and ultimately to the Proto-Indo-European root kʷetwóres, a fundamental numeral. "Bedroom" itself is a transparent compound from Old English elements describing a sleeping space. The logic of the compound is purely descriptive, specifying the quantity of a standard domestic feature, a formation common in real estate and property listings.

Structure: four (number) + bedroom (room for sleeping) - four: From Old English fēower, meaning the number 4. It functions as a numerical quantifier in the compound. - bedroom: A compound noun from bed (Old English bedd, a place for sleeping) + room (Old English rūm, space). It functions as the object being quantified.