Today's word indicates unknown origin with a guess at a possible permutation of "graft". I might suggest another origin. Seems I remember a word being used in old cowboy movies "grifter" and it referred to someone who unscrupulous and only drifting through town. Maybe it is a combination of Drifter and Graft. Which then was shortened and redefined as grift. Just a thought

hi (which coast?)
Sounds reasonable, but then English is so seldom sensible.

I remember it being used in the 50's,60's series "Cheyenne", starring Clint Walker.

High Plains Drifter, 1973. But wasn't Eastwood the good guy?

Maybe it is a combination of Drifter and Graft.

Doubtful. Graft in this sense, like grift, is of unknown origin, too.

I recall 'The Grifters' Anjelica Houston was memorable.

Okay, olly, put your eyes back in their sockets!