A good synonym, roughly translated, is "cariño," connoting a sense of love and caring, softness, or tenderness. Synonyms for the same word in Spanish parlance include the words: "ternura," and "pasión. "
"Carino" is the Spanish word for "affection. " In Spanish, there are two Ns, one that sounds like the N in "Nancy" and the other than sounds like the N in "senor. " The second N has a tilde over. "Carino" is pronounced "cah reen yo," more or less.
A common way to say endearment in Spanish is to say "le tengo mucho afecto" which means, literally, I have a lot of affection for it (or him, or her, or whoever).