transhumance

Concise Oxford English Dictionary © 2008 Oxford University Press:
transhumance /tranzˈhjuːməns, trɑːnz-, -ns-/

▶noun the action or practice of moving livestock seasonally from one grazing ground to another, typically to lowlands in winter and highlands in summer.

– derivatives
transhumant adjective.

– origin early 20th cent.: from Fr., from transhumer, based on L. trans- ‘across’ + humus ‘ground’.