Behind hand is a phrase that typically means to be late or lagging behind schedule. There are many different synonyms that can be used to convey a similar meaning, including overdue, tardy, behind schedule, running late, delayed, and lagging. Each of these words can be used in different contexts and in different ways to describe a situation where someone or something is not keeping up with expectations. Whether you are trying to describe a project that is falling behind schedule, a person who is constantly running late, or a task that is overdue, there are many different synonyms you can use to articulate the situation.