citron: thorny evergreen small tree or shrub of India widely cultivated for its large lemonlike fruits that have thick warty rind
citrus: any of numerous tropical usually thorny evergreen trees of the genus Citrus having leathery evergreen leaves and widely cultivated for their juicy edible fruits having leathery aromatic rinds
sloth: any of several slow-moving arboreal mammals of South America and Central America; they hang from branches back downward and feed on leaves and fruits