A hatch can refer to different things depending on the context. Here are some of the definitions of hatch based on the search results:

• A small door or opening in an airplane, spaceship, ship, or building.
• A trapdoor or other opening in the floor, ceiling, or wall that allows access.
• To mark or engrave with fine, crossed or parallel lines so as to achieve shading.
• To bring forth young from an egg or eggs by applying warmth.
• To create or decide on a plan, especially a secret plan.

As a noun, hatch can also refer to the cover for an opening, the process of hatching, or a surname.