A medicinal drug which is effective in the treatment of some disease(s), but which is not manufactured or marketed because the demand is insufficient to cover the costs of supply.

plural of half orphan

orphan drug

orphanage

plural of orphan disease

Any disease for which drugs are not usually developed because it is too rare to make the development profitable.

(physiology) A receptor that has a similar structure to other identified receptors but whose endogenous ligand has not yet been identified

plural of orphan drug

(astronomy) a star that is not part of any galaxy, but exists in intergalactic space instead

plural of orphan star