| ̷ ̷ ̷ ̷| ̷ ̷ transitive verb
Etymology: Middle English underminen, from under (I) + minen to mine — more at mine
1. : to excavate the earth beneath especially for the purpose of causing to fall : form a mine under : sap
undermine a wall
2.
a. : to wash away supporting material from under
flood water undermined the building's foundation
stream undermines the glacier
b. : to make a passage under
fence undermined by dogs
c. : to erode underneath or the underlayer of
an ulcer may undermine the adjacent mucous membrane
3. : to remove the foundation or support of subtly or by underhand means : subvert or weaken insidiously or secretly
the way a writer handles the social situation either supports or undermines it — Peter Crowcroft
selling below cost … to undermine competition — Time
undermine public confidence in its judicial system
4. : to weaken or ruin by degrees
prolonged overwork had undermined his health
Synonyms: see weaken