to hide: to put or keep someone or something out of sight, reach, or knowledge
At its core this word means to take something out of view, whether a person ducking out of sight, a fact kept secret, or God turning his attention away. The one idea of hiding runs through every use; what changes is who hides, from whom, and to what effect.
The Bible uses the word two opposite ways when God is the one hiding. To hide his face can be an act of judgment, a deliberate turning away that leaves a person feeling abandoned, and it can also be an act of care, tucking someone safely out of harm's reach. The same picture of being out of sight carries both the dread of being cut off and the comfort of being sheltered.
With people, the word most often means to take cover from danger: David hiding in a field, a prophet hiding by a brook, the prudent person slipping out of sight when trouble comes. It also covers keeping a matter concealed, so that a plan, a word, or even a person's whole situation stays unknown, sometimes from other people and sometimes, vainly, from God, who sees everything.