jerk

• n. 筋肉の痙攣；エキセントリックな人；愚か者；鋭い引きつけ
• vi.痙攣を起こす；鋭く引っ張る；でこぼこ道を移動する。
• vt.激しく引っ張る
• n.（ジャーク）人名；（ロシア語）エルク；（ハンガリー語）ジャーク

語源は不明だが、おそらくオノマトペからきている。語源jerk、dilettanteはスラングのjerk offから省略されたものかもしれない。

jerk (v.1)

"to pull," 1540s, "to lash, strike as with a whip," of uncertain origin, perhaps echoic. Related: Jerked; jerking.

jerk (v.2)

as a method of preserving meat, 1707, American English, from American Spanish carquear, from charqui (see jerky). Related: Jerked.

jerk (n.2)

"tedious and ineffectual person," 1935 (the lyric in "Big Rock Candy Mountain" apparently is "Where they hung the Turk [not jerk] that invented work"), American English carnival slang, of uncertain origin. Perhaps from jerkwater town (1878), where a steam locomotive crew had to take on boiler water from a trough or a creek because there was no water tank [Barnhart, OED]. This led 1890s to an adjectival use of jerk as "inferior, insignificant." Alternatively, or influenced by, verbal phrase jerk off "masturbate" [Rawson].

jerk (n.1)

1550s, "stroke of a whip," from jerk (v.1). Sense of "sudden sharp pull or twist" first recorded 1570s. Meaning "involuntary spasmodic movement of limbs or features" first recorded 1805. As the name of a popular dance, it is attested from 1966. Sense in soda jerk attested from 1883, from the pulling motion required to work the taps.

1. He indicated the bedroom with a jerk of his head.

彼は頭をひねって寝室の方向を指した。

2.He felt his head jerk reflexively.

彼は彼の頭が反射的に動いたと感じた。

3.Don 't jerk me around,Mr Crook.

ふざけるな、クルーさん。

4.It was a knee- jerk reaction on her part.

これは彼女が考えずにした反応だ。

5.The knife was stuck but she pulled it out with a jerk .

そのナイフは引っかかって、彼女はさっと抜いて、それを抜いた。