1. To physically conceal someone or something behind someone or something else. In this usage, a noun or pronoun is used between "hide" and "behind." I have no idea why the dog loves hiding his toys behind our dresser. I hid my drink behind my back so the photographer wouldn't capture me holding a bottle of beer.

2. To physically conceal oneself behind someone or something. My daughter always hides behind me at the first sound of fireworks—loud noises really scare her.

3. By extension, to use an idea, concept, or excuse as a means of concealment and/or evasion. She can try to deflect and distract by hiding behind whataboutism, but we all know she broke the law.