"jimmying"

[Joseph McCollum]

On Sat, 15 Jan 2000 22:06:18 -0500 Anne Lambert <annelamb at GNV.FDT.NET>
writes:
>Has anybody heard the word "jimmying" as in "I was jimmying around all
>day, driving from one errand to another" or "I was jimmying around
>trying to find the place"?  My mother(born Missouri 1894 of New
>England
>family) used it, but I have never heard anyone else who did/does, and
>it
>is not in DARE.

The only context in which I've heard it has been  "to jimmy a lock,"
meaning "to pick a lock."  I doubt it would have anything to do with GMC,
although I understand a device
that auto mechanics and car thieves use to open locked car doors is
called a "Slim Jim."