Antonyms for the phrase "doth something for" could include "neglects," "ignores," "abandons," "rejects," or "fails." When someone does something for another person, they are acting in a helpful or supportive manner. However, if someone neglects or ignores someone, they are not providing any assistance or support. Similarly, if someone abandons or rejects another person, they are not doing anything for them. Failing someone could also be considered an antonym, as it implies that the person did not receive the expected help or support. These antonyms suggest a lack of action, effort, or concern for others.