What does Gai Hua mean?

Umbrella roof.

Gai Hua is a Chinese word, which means an umbrella-shaped roof driven by an emperor. It can also refer to a balcony or roof supported by columns or protruding from a wall.

Gai Hua, a general star, is a numerology term and one of the four-pillar gods. The middle position of the triad is called the general star, and the general star likes the auspicious star gang. Killing it is auspicious, plus it is added.