Plain English Meaning
Bringing the airplane down from the air onto the runway in a smooth, controlled way and slowing it down safely.
Full Definition
The final phase of flight in which the airplane transitions from the air to the ground, consisting of a stabilized approach, roundout (flare), touchdown on the main wheels at minimum safe airspeed, and a controlled rollout along the runway centerline until the airplane is slowed to taxi speed.
Context Anchor
You encounter this term whenever the handbook discusses bringing an airplane from flight onto a runway or other .