citron Citrus medica, a citrus fruit resembling a huge, rough lemon. Some varieties may be as much as 30 cm (1') long. Most of the bulk is thick, dense rind; inside this the flesh is dryish and may be either sour or sweet, with a weak lemon flavour. The rind, which has a unique, resinous fragrance, is the most useful part.
The citron, like the lemon and lime, is native to NE India, where it was used from early times as a perfume and in medicine. The earliest reference to it is in the Vajasaneyi Samhita, a collection of religious texts dating from before 800 bc, in which it is called jambila. The fruit seems always to have had a curious connection with religion and magic, and a high reputation as medicine, being regarded as an antidote to almost any poison and indeed almost a panacea.