The term "attains majority" refers to the point in time when an individual becomes fully independent and is legally responsible for their actions. Antonyms for this term could include "remains a minor," "stays immature," or "forever dependent." These words would describe individuals who have not yet reached the age at which they are considered adults by law, or who have not yet achieved the level of maturity necessary to take on full responsibility for their actions. Other antonyms could include "fails to grow up," "never reaches adulthood," or "lacks responsibility." These all describe individuals who do not reach the legal or personal milestones that come with attaining majority.