Last name origins & meanings: 1  Chinese: although the character for Gan is the same as that in the name of the western province Gansu, the two sources of the surname are not related to that of the province. 2  One source of the surname is Gan Pan, a senior minister to the Shang dynasty king Wu Ding (1324–1266 bc). The other source is a town named Gan in Shaanxi province that was granted to a descendant of Wu Wang (who established the Zhou dynasty in 1122 bc). 2  The grantee’s descendants adopted the place name as their surname.