root out is a verb meaning "pull up by or as if by the roots". It carries 2 recorded senses.
pull up by or as if by the roots
“uproot the vine that has spread all over the garden”
destroy completely, as if down to the roots
“the vestiges of political democracy were soon uprooted”
“root out corruption”
Definitions, synonyms and semantic relations for root out come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.