1. Security is the greatest enemy. (¡¶¼Ó´ã¡· ¹æ½ÉÀÌ Á¦ÀÏ ¹«¼¿î ÀûÀÌ´Ù) 2. national security (±¹°¡ ¾Èº¸) 3. in security (¹«»çÈ÷) 4. He has given his house as security for the loan. (±× ´ëºÎ±ÝÀÇ ´ãº¸·Î ÁýÀ» ÀâÈ÷°í ÀÖ´Ù) 5. a security against burglars (µµµÏ¿¡ ´ëÇÑ ¹æÀ§)