security/ sɪ'kjuərɪtɪ /

1.noun [u] 
(precautions) 保安措施

The Queen's visit was marked by tight security.
女王的到访以保安严密著称。
2.noun [of country] [ border] [ building] [ person] 
安全

3.noun [of data] [ transaction] 
妥善保管

4.noun [of job etc] 
稳定性

fears about job security
对工作稳定性的担忧
5.noun
(emotional) 安全感

a sense of security
安全感
6.noun
(for loan) 抵押品

7.n pl [Finance] 
securities 证券

to increase/tighten security
增加/加强保安