1 a partner in a sexual relationship with sb who he/she is not married to (婚姻关系以外的)情人,爱人:
He discovered that his wife had a lover.他发现他的妻子有情人。The park was full of young lovers holding hands.公园里到处都是手挽着手的年轻情侣。
2 a person who likes or enjoys the thing mentioned (某事物的)爱好者,热爱者:
a music lover音乐爱好者an animal lover动物爱好者