Subsiding means to settle down or decrease. Its antonyms are to rise, increase, escalate, or intensify. Rising refers to an upward movement while an increase is the amount by which something grows. Escalating refers to a situation that becomes more intense or serious. Intensifying is to make something stronger or more extreme. All of these antonyms provide a way to express the opposite meaning of subsiding. For example, when a storm's wind is rising, it means that it is getting stronger, whereas when it is subsiding, it means that it is dying down.