a brief, sudden, often involuntary movement of a muscle or body part

• a small, nervous jerk

肌肉或身体部位短促突然的抽动，常为不自主的

• 细小的紧张性抖动

to jerk or spasm briefly, often involuntarily

短暂而不自主地抽动

to pull or jerk something sharply and briefly

猛地、短促地拉一下某物

a brief, sharp pull or jerk

短促而有力的一拉或一抖

a handle with a loop used on a horse’s lip or ear to restrain it

用于马匹的约束器具：带绳圈的棍柄，套在马唇或耳朵上使其安静

a single, brief contraction of a skeletal muscle in response to one stimulus

骨骼肌对一次刺激产生的单次短暂收缩

to travel, often quickly, to see a rare bird

为观赏稀有鸟而赶去某地（观鸟圈行话）

a trip made to observe a rare bird (birding jargon)

为观赏稀有鸟而进行的行程（观鸟圈行话）

a sudden narrowing of a vein of ore

矿脉突然变窄的部位