endearment

/ɪnˈdɪəmənt/
[C, U]
a word or an expression that is used to show affection 表示爱慕的话语；亲热的表示
They were whispering endearments to each other.
他们彼此低声倾吐着爱慕之情。
‘Darling’ is a term of endearment.
“亲爱的” 是一种昵称。