Usually the “something” is an insult or act of scorn, contempt, derision, or the like that we do not take, or intend to take, with the submission implied by recumbency, passively, that is.
In fact, he who does “take it lying down” is likely to be regarded as spineless, or perhaps as a bootlicker, stooge, apple-polisher, or toady.
It is an American expression, perhaps twenty-five or thirty years old.
