Webster's Revised Unabridged Dictionary · 1913

jerky

jerky , adjective

1.
Moving by jerks and starts; characterized by abrupt transitions; as, a jerky vehicle; a jerky style.
2.
Foolish; ridiculous; stupid. [slang]

jerky , noun

[Corrupted from Peruv. charqui dried beef.]

Meat, especially beef, that has been cut in strips and dried; meat that has been jerked; see first jerk, v.; as, beef jerky