"Sleep Tight"

Where do we get this phrase from...???

Well, it comes from Shakespearean England via thousands of children's bedtimes. William Shakespeare first gave "tightly" the meaning "effectively" or "well" in his 1598 play The Merry Wives Of Windsor.

 

By the late 18th century, the word was also used as an adjective, and it was in this form that it became part of rhyming couplet "Good Night. Sleep Tight", probably dreamed up by an anonymous mother to wish her young child a pleasant sleep. The subsequent popularity of this rhyme means that the phrase lives on today, despite its exact meaning being largely forgotten.