請問security是什麼意思

[美] [sɪˈkjurətɪ] [英] [siˈkjuːriti] 名詞安全,安全感[不可數名詞]Two guards looked after the security of the property. 兩個警衞看管財產的安全。證券,債券[P]He traded in securities and became rich. 他做證券交易發了財。保證;保障;擔保(品)[不可數名詞][可數名詞]A life-insurance policy may serve as security for a loan. 人壽保險可作貸款的抵押。

1、防備,保安;防護,防禦(措施)[不可數名詞][可數名詞][(+against/from)]They tightened security during the President's visit. 他們在總統訪問期間加強了安全防衞。