"Dropping the ball" is a phrase used to describe a situation where someone has failed to follow through on a task or responsibility. There are several synonyms that can be used to convey the same idea, including "falling short," "missing the mark," "failing to deliver," or "dropping the ball." Other possible phrases that can be used in place of "dropping the ball" include "letting someone down," "not living up to expectations," or "failing to meet a commitment." Overall, there are many different ways to talk about the disappointment that comes from someone failing to follow through on what they said they would do.