Definition of "shady"

The shady trees cover him with their shadow.

1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], Job 40:22

you may have rooms both for summer and winter; shady for summer, and warm for winter

1625, Francis [Bacon], “Of Building”, in The Essayes […], 3rd edition, London: […] Iohn Haviland for Hanna Barret

No sunshine in my life, the way I deal is shady

1991, “Blue Lines”, in Blue Lines, performed by Massive Attack

Jon & Kate Plus 8 is a show based on two facts: 1) Jon and Kate Gosselin have eight children, and 2) the word ‘Kate’ rhymes with the word ‘eight’. One suspects that if Kate were ever to have another child, a shady network executive would urge her to put it in a binbag with a brick and drop it down a well. But this is just a horrifying tangent.

2009: Stuart Heritage, Hecklerspray, Friday the 22nd of May in 2009 at 1 o’clock p.m., “Jon & Kate Latest: People You Don’t Know Do Crap You Don’t Care About”

They were being proper shady to him. Even if you don't like someone, locking them out, stealing their clothes and ganging up on them to take the piss is just childish.

2006 May 24, Saucy Jack, “BB7: Did Shabazz just deserve that?”, in uk.media.tv.misc‎ (Usenet)

I didn't even ask her to be in the 'Increase the Peace' campaign, which was well shady, 'cos if anyone knows anything about rudes and violence and getting dragged into stuff it's Uma.

2007, Grace Dent, Diary of a Chav 2: Slinging the Bling

"Don't be shady," she said, "You know I always pay up."

2007, Chastity Danielle Infinity, Jamo Lorswal, A Rose So That It May Rain, page 155