Something that's literally tangible can be touched. A rock is tangible, and so is a broken window; if the rock is lying next to the window, it could be tangible evidence of vandalism. When we say that the tension in a room is tangible, we mean we feel it so strongly that it seems almost physical. But if we're being literal, tension, like hope, happiness, and hunger, is literally intangible—it may be real, but it can't be touched. When lawyers talk about an intangible asset, they might mean something like a company's good reputation—very valuable, but not quite touchable.