thankless
adj. 不感谢的；忘恩的；不领情的；吃力不讨好的
例句
As Heidi did not want to appear thankless, she replied sadly, "I can't tell you."
因为海蒂不想显得忘恩负义，她伤心地回答：“我不能告诉你。”
Football referees have a thankless task.
足球裁判的工作费力不讨好。
《柯林斯英汉双解大词典》
Sometimes being a mother and a housewife felt like a thankless task.
做母亲和家庭主妇有时使人觉得好像是个受累不讨好的差使。
《牛津词典》
