prophylactic

名词 prophylactic:

1. remedy that prevents or slows the course of an illness or disease
   同义词：preventive, preventative
2. contraceptive device consisting of a sheath of thin rubber or latex that is worn over the penis during intercourse
   同义词：condom, rubber, safety, safe

形容词 prophylactic:

1. capable of preventing conception or impregnation
   同义词：contraceptive, antifertility
2. tending to ward off- Victor Schultze
   同义词：cautionary, preventive
3. preventing or contributing to the prevention of disease
   同义词：preventive, preventative

1. A prophylactic agent, device, or measure, such as a vaccine or drug.
   预防剂预防性的物质、器具或措施，比如疫苗或药物

pro.phy.lac.tic

adj.（形容词）
Acting to defend against or prevent something, especially disease; protective.
预防的：防范或预防某物的，比如疾病；保护性的
n.（名词）
A prophylactic agent, device, or measure, such as a vaccine or drug.
预防剂：预防性的物质、器具或措施，比如疫苗或药物
A contraceptive device, especially a condom.
避孕工具：预防怀孕的器具，尤指避孕套

来源：
French prophylactique
法语 prophylactique
from Greek prophulaktikos
源自 希腊语 prophulaktikos
from prophulassein [to take precautions against]
源自 prophulassein [对…提防]
pro- [before] * see pro- 2
pro- [有…之前] *参见 pro-2
phulassein [to protect] from phulax [guard]
phulassein [保护] 源自 phulax [守卫]

【引伸】
pro.phylac.tically
adv.（副词）