lone        
adjective [ before noun ] uk/ləʊn/ us/loʊn/
 单独的,独自的
alone
  a lone survivor 唯一的幸存者 
 He was a lone voice (= the only person) arguing against a reduction in payments. 他是唯一反对减薪的人。 
 lone parent/mother/father 单亲/单身母亲/单身父亲
someone who has children but no partner living with them