"to pull with sudden energy," 1580s; earlier "to lash, strike as with a whip" (1540s, surviving only in dialect), of uncertain origin, perhaps echoic. Intransitive sense of "make a sudden spasmodic motion" is from c. 1600. Compare Middle English yerkid, an adjective apparently meaning "pulled tight" (early 15c.), which has the form of a past participle. Also compare Middle English ferken "move hastily; drive (something) forward," from Old English fercian "to proceed." Related: Jerked; jerking.

"tedious and ineffectual person," 1935, American English carnival slang, of uncertain origin. Perhaps from jerkwater "petty, inferior, insignificant" [Barnhart, OED]; alternatively from, or influenced by, verbal phrase jerk off "masturbate" [Rawson]. The lyric in "Big Rock Candy Mountain," sometimes offered as evidence of earlier use, apparently is "Where they hung the Turk [not jerk] that invented work."

A soda-jerk (1915; soda-jerker is from 1883) is so called for the pulling motion required to work the taps.

The SODA-FOUNTAIN CLERK

Consider now the meek and humble soda-fountain clerk,

Who draweth off the moistened air with nimble turn and jerk,

[etc., Bulletin of Pharmacy, August, 1902]

1550s, "stroke of a whip," from jerk (v.1). Sense of "sudden sharp pull or twist" is by 1570s. Meaning "involuntary spasmodic movement of limbs or features" recorded from 1805. As the name of a popular dance, it is attested from 1966.

"preserve (meat) by cutting into long thin strips and drying in the sun," 1707, American English, from American Spanish carquear, from charqui (see jerky). Related: Jerked.

patellar reflex, a neurological phenomenon discovered and named in 1876; see knee (n.) + jerk (n.1) in the medical sense. The figurative use appeared soon after the phrase was coined.

slang, "perform male masturbation," by 1896, from jerk (v.) denoting rapid pulling motion + off (adv.). Compare come off "experience orgasm" (17c.). Farmer and Henley ("Slang and Its Analogues") also lists as synonyms jerk (one's) jelly and jerk (one's) juice. The noun jerk off or jerkoff as an emphatic form of jerk (n.2) is attested by 1968. As an adjective from 1957.

1940s, "masturbator," British slang, from wank "to masturbate," of unknown origin. General sense of "contemptible person" is attested from 1972. Compare sense evolution of jerk (n.).

1911, in reference to newspaper stories about tragic situations, on model of soda-jerker and perhaps especially beer-jerker, from tear (n.1) + jerk (v.).

"characterized by jerks, spasmodic," 1819, originally in medical writing with reference to the pulse, from jerk (n.1) + -y (2). Related: Jerkily; jerkiness.