Gua Pi is a dialect of Shaanxi, meaning: not smart enough, or unresponsive.
There is also melon goat, melon baby, stupid, retarded, equivalent to the Mandarin "goat", "stupid" with contempt. And in Sichuan, Chongqing dialect, not entirely derogatory, is one of the people often say one of the mantra, positive or negative, and sometimes as close to the person's nickname, compared to the "stupid", "stupid".
Central Plains Official Dialect - Guanzhong Dialect
Guanzhong Dialect belongs to the Central Plains Official Dialect, and is a branch of it, with Xi'an Dialect (Dongfu) and Baoji Dialect (Xifu) as its representative dialects. Guanzhong dialect is divided into Guanzhong Dongfu dialect and Guanzhong Xifu dialect.
The former includes Xi'an, Weinan, Tongchuan, Xianyang, Shangzhou-Lonan-Danfeng-Sanyang under Shangluo, Yichuan-Huanglong-Lochuan-Yijun in northern Shaanxi Province -Huangling-Fuxian, Yuncheng-Linfen in Shanxi, and Lingbao in Henan. The latter includes the cities of Baoji, Gansu Tianshui, Qingyang, Pingliang and southwestern Ningxia.
Guanzhonghua is one of the most representative dialects of northwest China. People who speak Shaanxi dialect (Guanzhonghua) are mainly concentrated in the Guanzhong area, which extends from Lingbao in Henan Province in the east to the Tianshui area in Gansu Province in the west, and connects to Yan'an in the north and extends to the northern foothills of the Qinling Mountains in the south, with a total population of about 50 million people.