hospitaller

The word "hospitaller" comes from the medieval world and refers chiefly to a member of a religious order connected with hospitality, charity, and care for the sick and for travelers. It is most strongly associated with the Knights Hospitaller, also known as the Order of Saint John. These members were known for maintaining hospitals and for helping pilgrims by giving them food, shelter, care, and sometimes protection.

Because the word is so tied to that historical setting, it is not usually used today for just any kind or welcoming person. Calling a modern innkeeper, volunteer, or town "hospitaller" would sound unusual unless you were making a historical comparison or using the word in a poetic way. In normal English, people are more likely to say "hospitable," "charitable," or "welcoming."

So the safest understanding is this: a hospitaller is usually a historical religious figure, especially one whose duty involved caring for guests, pilgrims, or the sick. The word carries ideas of service and mercy, but its meaning is narrower than simple hospitality.

You are most likely to see the term in writing about medieval history, religious orders, crusading orders, or the history of hospitals and charitable care. In those contexts, "hospitaller" makes clear sense. Outside them, it can still be understood, but it tends to sound literary or old-fashioned.