Citron
A source of confusion is that "citron" or similar words in French (and other languages), and English are false friends, as they refer to the lemon. Indeed, into the 16th century, the English name "citron" included the lemon and perhaps the lime as well.
Saint Clement's (cocktail)
The Saint Clement's is a non-alcoholic cocktail. Though the ingredients may vary, it consists of orange juice mixed with bitter lemon, usually in equal proportions; the name of the drink refers to the English nursery rhyme Oranges and Lemons. The drink is therefore named (indirectly) after either St Clement Eastcheap or St Clement Danes, both churches in London. The traditional recipe calls for equal parts orange juice and lemon juice served over ice in a highball glass. There are many variations, in which the lemon juice is replaced with a sweeter drink (like lemonade), or even a carbonated citrus-flavored soft drink (like Sprite, 7-Up, or Fanta Lemon).