I grew up in the country, but lived near a little neighborhood that was referred to as "the allotment." I didn't really understand the literal definition of that word. I just realized that if you lived in "the allotment," it meant you had close neighbors!
An "allotment" of sorts is going on in Joshua 18. So far, the tribes of Gad, Reuben and Manasseh (1/2 tribe) had received their portion in the east, beyond the Jordan. The tribes of Judah and Ephraim (1/2 tribe) had received their inheritance in the south and north respectively. The tribe of Levi would be receiving no designated land since they belonged to the Lord. That leaves seven tribes remaining without a designated inheritance.
Joshua seems a little displeased that the disposition of the land to the tribes is taking so long. He comes up with a plan: three men from each tribe are designated to go map out the land and break it into seven regions for the remaining tribes. Lots will then be cast to determine who gets what lot.
The first tribe to be picked in this manner for their inheritance is Benjamin, and the description of their land with its boundary markers follow. Benjamin now has a home!