Gerrymander

Merriam-Webster Online Dictionary
gerrymander (noun)
1.
the act or method of - gerrymandering
2.
a district or pattern of districts varying greatly in size or population as a result of gerrymandering
gerrymander (verb)
transitive verb
1.
to divide (a territorial unit) into election districts to give one political party an electoral majority in a large number of districts while concentrating the voting strength of the opposition in as few districts as possible
2.
to divide (an area) into political units to give special advantages to one group - gerrymander a school district