self-preservation
noun [ U ] uk/ˌselfˌprez.əˈveɪ.ʃən/ us/ˌselfˌprez.ɚˈveɪ.ʃən/
自保，自我保护
behaviour based on the characteristics or feelings that warn people or animals to protect themselves from difficulties or dangers
It was his instinct for self-preservation that led him to abandon his former friends and transfer his allegiance to the new rulers. 正是他自保的本能驱使他抛弃了以前的朋友，转而效忠于新的统治者。