*** English Shopping

Let it rip let something go at full speed, take off all restraints(<자동차 등을> 맹렬히 몰다): He let it rip and left the shore in the motorboat.
Let off steam get rid of your extra energy or strong feelings by doing some activity(울분[열기 등]을 발산하다, 기분 풀다): He was very angry at first but he has let off steam and has calmed down now.
Let on to allow to be known; admit(인정하다, 밝히다): Don't let on that you know me.
Let on to try to make people believe something, pretend(가식적으로 행동하다): He tried to let on that he didn't want the job but actually he did.
Let one's guard down relax and stop looking out for danger(경계심을 늦추다): Never let one's guard down.