to be economical with the truth --------- 撒谎（委婉语）

英文释义
(EUPHEMISM) To lie.

例句
Our little son likes to take cookies, and when we ask him about any that are missing, he often seems to be somewhat economical with the truth.
我们的小儿子喜欢吃饼干，当有饼干消失，我们去问他时，他经常看上去像是在撒谎。