failபொய்யாக்குpoyyākku(poyyaakku)(3 tr)fail to accomplish or achieve a goal; be unsuccessful in justifying or proving; be unsuccessful in examinations; go back (on o's word); err; omit or neglect (as a duty)
Usage:
வக்கீல் நம்முடைய வழக்கை பொய்யாக்கினார்vakkīl nammuṭaiya vaḻakkai poyyākkiṉār
vakkiilu namma vaḻakke poyyaakkunaaru
the lawyer failed to make a strong stand for our case.