Ever wondered what this phrase meant? I get to see many wishing 'Sleep Tight' along with the usual phrases -- Good Night and Sweet dreams. Whenever I come across a new term and when it is repeated some 3 to 5 times and when I dont understand completely what does it mean, I get slightly uncomfortable with my knowledge of words. Also I fear that some terms could mean offensive and hurt the reader. Hence, I dont use it myself unless I find the meaning of it. So, I get to search on this term 'Sleep tight' today. My google research goes this way.
The phrase is nearly in practise from the late 20th century. The first citation of this phrase is as early as 1866. In her diary Through Some Eventful Years, Susan Bradford Eppes included:
"All is ready and we leave as soon as breakfast is over. Goodbye little Diary. ‘Sleep tight and wake bright,’ for I will need you when I return."
In 1968, it was also used in a song by Lennon and McCartney as
Now it's time to say good night,
Good night. Sleep tight.
Good night and sleep tight are so rhyming that it soon got spread so fast. But why to sleep tight? Is it something related to the person sleeping is wearing tight clothes while sleeping.. No.... its not.. There was one notion -- Earlier days, the cot, in which people sleep had ropes on it and those ropes had to be tightened before sleeping. You would have come across such cots in ur grandma's house or in some movies shot in a village home. The origin of the word has a link to this idea, but no it is not the final conclusion.
After much research, the OED(Oxford English Dictionary) team concluded that by the time the phrase was used among people, rope-strung beds were replaced by metal-strings. Hence there is no link between sleep tight and cots. 'Sleep tight' just means 'sleep soundly'; put it in another words the meaning of 'tight asleep' is 'soundly asleep'.
Finally I am happy to know the origin and meaning of this term today. Will be using it from now on in my sms. :) without any fear.