Main Entry: un·der·mine

Pronunciation: \ˌən-dər-ˈmīn\

Function: transitive verb

Date: 14th century

1 : to excavate the earth beneath : form a mine under : sap
2 : to wash away supporting material from under
3 : to subvert or weaken insidiously or secretly <trying to undermine his political rivals>
4 : to weaken or ruin by degrees

synonyms see weaken