Antonyms for the phrase "get one started" would include words and phrases that signify the opposite of inciting action and motivation. Some possible antonyms might include "hold back," "impede," "discourage," "deter," "hinder," "prevent," or "stifle." These words suggest a reluctance to begin something or an active resistance to moving forward. Antonyms for the phrase might also include words or phrases that indicate a lack of enthusiasm or interest, such as "ignore," "neglect," "disinterest," or "abandon." Together, these antonyms provide a picture of the obstacles and challenges that can stand in the way of getting started on a new project or pursuit.