The phrase "take up for" generally refers to defending or supporting someone or something. There are many synonyms that can be used to convey similar meanings, including "stand up for," "champion," "advocate," "uphold," and "back up." Each of these terms implies a sense of loyalty or commitment to the person or cause being supported. Other possible synonyms for "take up for" might include "protect," "defend," "side with," "align oneself with," or "be in favor of." Ultimately, the choice of synonym may depend on the particular context in which the phrase is being used and the specific shade of meaning that the speaker wishes to convey.