A pinch-hitter is a term commonly used in baseball to describe a player who substitutes in for another player who is not performing up to standards. However, there are many other synonyms for "pinch-hitters" that can be used in different contexts. Some of these synonyms include "substitute," "stand-in," "replacement," "backup," "fill-in," and "relief player." Each of these terms implies a similar idea of stepping in for someone else in a time of need. Whether it be in sports or in everyday life, these synonyms can be used to describe someone who is ready and willing to take on a task at a moment's notice.