piston

n. 活塞, 活塞阀键
【医】 活塞(如注射器的)

pis.ton

n.（名词）
A solid cylinder or disk that fits snugly into a larger cylinder and moves under fluid pressure, as in a reciprocating engine, or displaces or compresses fluids, as in pumps and compressors.
活塞：一种可装到更大的筒里且在液压下移动的固体小筒或碟子，如在往复式发动机中，也可用于更换或压缩液体，如在水泵和压缩机上
Music A valve mechanism in brass instruments for altering the pitch.
【音乐】 活塞阀键：一种铜管乐器上调节音量的活塞阀键

来源：
French
法语
from Italian pistone, pestone [large pestle]
源自 意大利语 pistone, pestone [大杵]
from pestare [to pound, crush]
源自 pestare [捣，弄碎]
from Late Latin pist3re
源自 后期拉丁语 pist3re
frequentative of Latin ponsere, pons3re
拉丁语 ponsere的重复, pons3re