A horizontal door in a floor or ceiling.

A trapdoor.

An opening in a wall at window height for the purpose of serving food or other items. A pass through.

A small door in large mechanical structures and vehicles such as aircraft and spacecraft often provided for access for maintenance.

(nautical) An opening through the deck of a ship or submarine

(slang) A gullet.

A frame or weir in a river, for catching fish.

A floodgate; a sluice gate.

(Scotland) A bedstead.

(mining) An opening into, or in search of, a mine.

The act of hatching.

(figurative) Development; disclosure; discovery.

(poultry) A group of birds that emerged from eggs at a specified time.

(often as mayfly hatch) The phenomenon, lasting 1–2 days, of large clouds of mayflies appearing in one location to mate, having reached maturity.

(informal) A birth, the birth records (in the newspaper).

(transitive) To close with a hatch or hatches.

(intransitive, of young animals) To emerge from an egg.

(intransitive, of eggs) To break open when a young animal emerges from it.

(transitive) To incubate eggs; to cause to hatch.

(transitive) To devise (a plot or scheme).

(transitive) To shade an area of (a drawing, diagram, etc.) with fine parallel lines, or with lines which cross each other (cross-hatch).