Definition of "cantrip"

Coffins stood round, like open presses, That shaw’d the dead in their last dresses;And by some devilish cantrip slightEach in its cauld hand held a light […]

1791, Robert Burns, "Tam o' Shanter", lines 125-8

I have some poor little skill—not like yours, Master Doctor, of course—in small spells and cantrips that I’d be glad to use against our enemies if it was agreeable to all concerned.

1951, C. S. Lewis, chapter 12, in Prince Caspian, Collins, published 1998

For one thing, I've no intention of distributing cantrips and costly crucifixes to every rapable woman in the Parish of St Magloire.

1976, Kyril Bonfiglioli, Something Nasty in the Woodshed, Penguin, published 2001, page 422

And when I say now the power of the name Jesus makes you whole, I indulge in no petty mountebank’s cantrips.

1984, Anthony Burgess, The Kingdom Of The Wicked

But it sounds to me like you're in a totally different category. Not garden-variety cantrip stuff.

2009, James Patterson, Gabrielle Charbonnet, Witch and Wizard, Little, Brown and Company, page 148