1. 伸长：protractile 伸出的 | protraction 伸长 | protractor 量角器
2. 前伸：protracted labor 滞产 | protraction 前伸 | protrusion 伸出
3. 延长;伸展;拖长;绘制：protracted 延长的 | protraction 延长;伸展;拖长;绘制 | protractor 量角器
4. 延長;製圖：原型反應器 prototype reactor | 延長;製圖 protraction | 延長劑量 protraction dose
protraction的意思
noun
1. the act of prolonging something
e.g. there was an indefinite prolongation of the peace talks
Synonym: prolongationperpetuationlengthening
2. the consequence of being lengthened in duration
Synonym: lengthinessprolongationcontinuation