"Take on" is a common phrase used in both casual and formal language, and it can mean a variety of things depending on the context. When used to describe accepting a responsibility or a challenge, synonyms for "take on" could include: assume, undertake, shoulder, adopt, embrace, or tackle. Alternatively, "take on" can refer to hiring someone for a job or a task, for which suitable synonyms might include: recruit, employ, engage, appoint or select. Other possible synonyms for the phrase "take on" could include grab, acquire, accept, absorb, or confront, depending on the situation in which the phrase is used.