'door-to-door' originates from English, formed by compounding the word 'door' + the preposition 'to' + 'door'; the element 'door' itself comes from Old English 'dor' (also attested as 'duru'), where that word meant 'a doorway, gate, or entrance'.

The element 'door' changed from Old English 'dor' (and earlier Proto-Germanic '*durz') and eventually became the modern English 'door'. The compound phrase 'door-to-door' developed later in modern English to describe movement or activity from one house to another (for example, selling or canvassing).

Initially 'door' referred to the physical barrier or entrance; over time the compound 'door-to-door' came to mean 'from one house to another' (i.e., visiting each household) and is now commonly used to describe sales, canvassing, or similar activities.