Main Entry: bar·ri·er

Pronunciation: \ˈber-ē-ər, ˈba-rē-\

Function: noun

Etymology: Middle English barrere, from Anglo-French, from barre bar

Date: 14th century

1 a : something material that blocks or is intended to block passage <highway barriers> <a barrier contraceptive> b : a natural formation or structure that prevents or hinders movement or action <geographic barriers to species dissemination> <barrier beaches> <drugs that cross the placental barrier>
2 plural often capitalized : a medieval war game in which combatants fight on foot with a fence or railing between them
3 : something immaterial that impedes or separates : obstacle <behavioral barriers> <trade barriers>