n.
Function: noun
Date: 1693
1 : the isolation by a warring nation of an enemy area (as a harbor) by troops or warships to prevent passage of persons or supplies broadly : a restrictive measure designed to obstruct the commerce and communications of an unfriendly nation
2 : something that blocks
3 : interruption of normal physiological function (as transmission of nerve impulses) of a cellular receptor, tissue, or organ also : inhibition of a physiologically active substance (as a hormone)