tophu

n.; pl. Tophi [ NL.: cf. F. tophus a mineral concretion in the joint. See Toph. ] [ Written also tofus. ] 1. (Med.) One of the mineral concretions about the joints, and in other situations, occurring chiefly in gouty persons. They consist usually of urate of sodium; when occurring in the internal organs they are also composed of phosphate of calcium. [ 1913 Webster ]

2. (Min.) Calcareous tufa. [ 1913 Webster ]