Original: In meteorology, an anticyclone (that is, opposite to a cyclone) is a weather phenomenon in which there is a descending movement of the air, and with surface systems, higher than average atmospheric pressure over the part of the planet's surface.
Simplified: In meteorology, an anticyclone (that is, opposite to a cyclone) is a weather event where there is a downward movement of the air and a high pressure area over the part of the planet's surface affected by it.