There are two meanings of this aviation term. 1)An irregular | ✈️Aviation English

There are two meanings of this aviation term.

1)An irregular or emergency landing in which an aircraft drops flat to the ground from a low altitude.

2) The aircraft lands without its landing gear fully extended and uses its belly, as its primary landing device.

There is also a verb -to pancake.
(The aircraft pancaked on the runway.There wasn't significant damage to a plane owing to the airmanship of the pilots.)