名詞 preventive:

1. remedy that prevents or slows the course of an illness or disease
   同義詞：preventative, prophylactic
2. any obstruction that impedes or is burdensome
   同義詞：hindrance, hinderance, hitch, preventative, encumbrance, incumbrance, interference
3. an agent or device intended to prevent conception
   同義詞：contraceptive, preventative, contraceptive device, prophylactic device, birth control device

形容詞 preventive:

1. preventing or contributing to the prevention of disease
   同義詞：preventative, prophylactic
2. tending to prevent or hinder
   同義詞：preventative
3. tending to ward off- Victor Schultze
   同義詞：cautionary, prophylactic

1. Something, such as a ritual practice or sacred object, believed to control natural or supernatural powers or serve as a preventive or remedy.
   巫術(shù)，魔力被認(rèn)為是控制著自然或超自然力量的東西或是可以作為預(yù)防性藥物或治療物的東西，例如宗教儀式或圣物
2. We had to take preventive measures.
   我們不得不采取預(yù)防措施。
3. Please take some preventive medicine now.
   請吃些預(yù)防藥吧。

pre.ven.tive

adj.（形容詞）
Intended or used to prevent or hinder; acting as an obstacle:
預(yù)防的：打算或用來預(yù)防或阻止的；作為障礙的：
例句：
preventive measures.
預(yù)防措施

Carried out to deter expected aggression by hostile forces.
防止的：實(shí)施以用來防止敵對勢力有可能的進(jìn)攻的
Preventing or slowing the course of an illness or a disease; prophylactic:
防病的：預(yù)防或延緩病情發(fā)展的；預(yù)防性的：
例句：
preventive medicine; preventive health care.
預(yù)防藥，預(yù)防性保健

n.（名詞）
Something that prevents; an obstacle.
預(yù)防物：起預(yù)防作用的東西；阻礙
Something that prevents or slows the course of an illness or disease.
預(yù)防藥，預(yù)防法，預(yù)防措施：預(yù)防或延緩病情發(fā)展的藥品，方法或措施

【引伸】
preven.tively
adv.（副詞）
preven.tiveness
n.（名詞）