sweetheart

sweetheart /ˈswiːtˌhɑɚt/ noun
plural sweethearts
sweetheart
/ˈswiːtˌhɑɚt/
noun
plural sweethearts
Britannica Dictionary definition of SWEETHEART
1 
a  [count] somewhat old-fashioned : a person you love very much
b  — used to address someone you love
2 
[count] : a kind or helpful person : someone who is very nice