The phrase "hold in subjection" refers to the act of controlling or dominating someone or something. There are many synonyms that share a similar meaning to this phrase, including "subjugate," "enslave," "oppress," "dominate," "restrain," "conquer," "suppress," "control," and "manage." Each of these words implies a level of power and authority over another, whether it be an individual or group. It is essential to note that holding something in subjection can be achieved through various means, including physical violence, manipulation, or coercion. The use of these synonyms can help to convey the severity and gravity of such acts of domination.