The phrase "kept under one thumb" means to control or dominate someone completely. Antonyms for this phrase include liberate, emancipate, empower, free, release, unbind, untie, unlock, unleash, unshackle, and unhand. These words describe the opposite action of "keeping someone under one thumb," indicating that the person is not being suppressed or restrained. These terms imply an atmosphere of independence, where the control has been taken away from the dominating person, and the person is free to make their own choices. Overall, using antonyms of "kept under one thumb" can evoke feelings of empowerment and liberation.