Hospital Ship
A Hospital Ship or medical ship is a starship whose primary function was to be used for medical purposes. This could include serving as a hospital, ambulance, or pharmacy. Because of this, they were typically not well armed with weapons or other defensive systems.
Various cultures had ships of this nature, including the Federation.
In an alternate timeline, one such hospital ship was the USS Pasteur. (TNG: "All Good Things...").
The USS McCoy participated in recovering wounded during the battle of Sector 001 at the end of the Federation Civil War.
One subject discussed at a conference on Romulus during the Dominion War in 2375 was a proposal to transfer 25 Federation hospital ships to the Romulans. (DS9: "Inter Arma Enim Silent Leges")
In 2377, USS Voyager came across a Kraylor medical ship that Harry Kim named Nightingale. (VOY: "Nightingale")
The Denobulans used medical ships to transport their medical supplies. (ENT: "Cold Station 12")