What does adjoin mean?
To adjoin is to lie next to something else, sharing a common boundary or wall — most often said of buildings, rooms, or parcels of land. A kitchen may adjoin a dining room, a garden may adjoin a neighbour's property, and hotel rooms that adjoin are connected by an internal door. The word carries a precise, slightly formal tone, which makes it a staple of architectural plans, estate listings, and legal documents describing exactly where one piece of property ends and another begins. In everyday speech, people tend to say 'next to' or 'attached to', but 'adjoin' offers a compact way to express physical contact between two things without ambiguity. Its most familiar descendant in daily use is the adjective 'adjoining', as in 'adjoining rooms' — a phrase so common in the travel industry that it has become part of the standard vocabulary of hotels worldwide. For anyone writing about space, boundaries, or proximity with precision, 'adjoin' is a small word that earns its keep.
verbTo be next to or in contact with something, especially of buildings, rooms, or pieces of land sharing a common boundary. It can also mean to attach or join something to another thing.
- (Of buildings, rooms, or land) to be next to and share a boundary or wall with another.
- To attach, join, or add something to something else (less common, often formal).
"The hotel's ballroom adjoins the main lobby, making it easy for guests to move between events."
"The kitchen adjoins the dining room through a wide archway."
"The two properties adjoin along the northern fence line."
If your hotel room 'adjoins' the one next door, you share a door — a fact that has made 'adjoining rooms' one of the most searched phrases in travel.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of adjoin
The verb 'adjoin' entered English in the late Middle Ages, borrowed from Old French 'ajoindre', which itself derives from the Latin 'adiungere', meaning 'to join to'. This Latin compound combines 'ad-' ('to, toward') with 'iungere' ('to join'), the same root that gives us 'join', 'junction', and 'yoke'-related words via its Indo-European ancestry. Cognates include 'adjacent' (from Latin 'adjacēre') and 'conjugate' (from 'coniungere'), all built on the same idea of bringing things into contact. The word has remained remarkably stable in meaning since its adoption, consistently denoting physical contact or shared boundaries.
Related word forms
How adjoin is actually used
Most commonly used in real estate, architecture, and legal descriptions of property. The past participle form 'adjoining' is far more frequent than the verb itself in everyday usage, as in 'adjoining rooms' or 'an adjoining garage'. Slightly formal register; in casual speech people more often say 'next to' or 'attached to'.
Easily confused with adjoin
'Adjoin' means to be next to or attached to something, while 'adjourn' means to suspend a meeting or session until a later time.