名詞 ratchet:

1. mechanical device consisting of a toothed wheel or rack engaged with a pawl that permits it to move in only one direction
   同義詞：rachet, ratch

動詞 ratchet:

1. move by degrees in one direction only
   同義詞：rachet up, ratchet down

ratch.et

n.（名詞）
A mechanism consisting of a pawl that engages the sloping teeth of a wheel or bar, permitting motion in one direction only.
棘輪，棘爪：一種包含合于轉(zhuǎn)輪或長條傾斜性齒輪中的爪狀物的機械，使輪僅向一個方向運動
The pawl, wheel, or bar of this mechanism.
棘輪，棘爪，棘條：這種機械裝置中的爪狀物，轉(zhuǎn)輪或長條
v.tr.（及物動詞）
ratch.et.ed,ratch.et.ing,ratch.ets
To increase or decrease by increments. Often used withup, upward, down, or downward :
漸進：一步步地增加或減少。通常與up,upward,down 或 downward 一起使用：
例句：
.Some companies . . . may make things worse if they seek to ratchet down their medical expenses by limiting benefits for psychological or psychiatric care.(Newsweek)
.有些公司企圖限制精神或心理衛(wèi)生上的福利來減少醫(yī)療開支，那它們只會把事情搞得更糟.(新聞周刊)

來源：
French rochet
法語 rochet
from Old French rocquet [head of a lance (from the shape of the teeth)]
源自 古法語 rocquet [長矛尖端（由齒狀而來）]
[of Germanic origin]
[來源于德語]