The word "am" is a form of the verb "to be," which is used in the present tense for first-person singular. There are several synonyms for this word, including "exist," "subsist," "occur," "happen," and "take place." Each of these words is similar in meaning to "am" in that they all refer to some sort of state of being or occurrence. However, each of these words has slightly different connotations and can be used in different contexts. For example, "exist" generally refers to a more permanent state of being, while "occur" and "happen" imply more of a temporary or fleeting state.