Main Entry: pos·tern

Pronunciation: \ˈpōs-tərn, ˈpäs-\

Function: noun

Etymology: Middle English posterne, from Anglo-French, alteration of Old French posterle, from Late Latin posterula, diminutive of postera back door, from Latin, feminine of posterus

Date: 14th century

1 : a back door or gate
2 : a private or side entrance or way

— postern adjective