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4.
When everything is funny.. usually using motion lotion.. blow up dolls.. right hand.. etc.. fone sex.. ne thing funny .. nothing on tv up late.. nothing to watch and its funny
im so nighthigh i can actually see stars while you are standing out side
whoa.. i see purple cows.. kuew.. "ehe..ehehe ahahah!!!"
by [ Deejay La0ziE ] Jimmy April 18, 2003
 
1.
To be so tired that it would seem to others that you are, in a sense, high. Most commonly happens late at night, and symptoms include random bursts of laughter and well, other stuff people do when there high.
Jacob-hehehehe look at that door, its so, white and beautiful.
John-ya jacob, u a little night high or what?
by JakeC August 16, 2007
 
2.
The physical and/or mental state in the very late hours where you are tired and not in control or just not caring about what you say or do. Easily avoided by going to sleep or drinking excess amounts of high caffine products.
Last night John was speaking nonsense about some magic unicorn steal his lucky charms??!

Oh he musta had a night high...he shouldnt stay up so late.
by SHADY225 June 02, 2009
 
3.
When your always hyper at night time. When your jittery, like you just ate a bunch of sugar.
You: OMGOMGOMG
Friend: Your night high bro.
by KJo990 November 11, 2012