jerky (n.) Look up jerky at Dictionary.com
1850, American English, from American Spanish charqui "jerked meat," from Quechua (Inca) ch'arki "dried flesh."
jerky (adj.) Look up jerky at Dictionary.com
"characterized by jerks," 1858, from jerk (v.1) + -y (2). Related: Jerkily; jerkiness.