Definition of "spade"

'Make your mind easy,' Ratsey said; 'I have dug too often in this graveyard for any to wonder if they see me with a spade.'

1898, J. Meade Falkner, chapter 4, in Moonfleet, London, Toronto, Ont.: Jonathan Cape, published 1934

"[...] And not a single spade has gone in the ground - not a single mile of track built."

2021 October 6, Paul Stephen, “Network News: Labour: build HS2 and NPR and end "paper promises"”, in RAIL, number 941, page 25

And as for a divorce, I know plenty spades right here in Harlem get married any time they want to.

1929, Wallace Thurman, The Blacker the Berry, New York: Collier Books, published 1970, page 161

Example: Max was in a hospital in New York and "the night nurse was a groovy spade, and in the afternoon for therapy there was a chick from Israel who was interesting, but there was nothing much to do in the morning, so I left".

1968, Joan Didion, “Slouching Towards Bethlehem”, in Slouching Towards Bethlehem

It had even gotten to the point that Negroes were no longer in the hip scene, not even as totem figures. It was unbelievable. Spades, the very soul figures of Hip, of jazz, of the hip vocabulary itself, man and like dig and baby and scarf and split and later and so fine, of civil rights and graduating from Reed College and living on North Beach, down Mason, and balling spade cats—all that good elaborate petting and patting and pouring soul all over the spades—all over, finished, incredibly.

1968, Tom Wolfe, The Electric Kool-Aid Acid Test, Bantam, published 1997, page 9