An·schluss (än'shlŏŏs') n. A political union, especially the one unifying Nazi Germany and Austria in 1938.
[German, annexation, from anschliessen, to enclose, annex : an, on (from Middle High German ane, from Old High German ana; see an- in Indo-European roots) + schliessen, to close (from Middle High German sliezen, from Old High German sliozan).]
1924, from Ger., lit. "joining, union," from anschliessen "to join, annex," specifically the proposal to unite Germany and Austria, accomplished in 1938.