rough lemon
noun
A kind of lemon tree, Citrusx jambhiri, often used as a rootstock for raising other citrus fruits; (also) the fruit of this tree, which has thick skin and relatively little juice compared to other varieties and so is rarely cultivated.
- The rough lemon is thought to be a hybrid between the lemon and the citron, but its exact taxonomic position is unresolved..
Origin
Late 19th century; earliest use found in Milwaukee News.