Ebb means to flow back or recede, like water moving away from shore as the tide goes out. When you stand at the beach and watch the waves pull back, leaving wet sand and shells behind, you're watching the tide ebb. The opposite happens during flow or flood tide, when water rushes toward the shore.

The word also describes anything that decreases or weakens gradually. Your energy might ebb as the school day goes on, or a crowd's excitement might ebb after the most thrilling part of a performance ends. When someone's confidence ebbs, it drains away bit by bit.

People often use the phrase ebb and flow to describe natural cycles of increase and decrease. A friendship might have its ebb and flow, with times when you see each other constantly and times when you drift apart. A student's motivation might ebb and flow throughout the year. The phrase captures how many things in life move in rhythms, rising and falling like ocean tides, rather than staying constant.

When something reaches its lowest point, you might say it's at low ebb or at an ebb. After weeks of hard work, your enthusiasm for a project might be at a low ebb, ready to rise again after some rest.