There are a variety of synonyms for the phrase "load down," which refers to burdening someone or something with a heavy weight or responsibility. Some possible alternatives include "weigh down," "oppress," "overwhelm," "encumber," "saddle," "plague," "burden," and "tax." Each of these terms conveys a certain sense of difficulty or hardship that comes with carrying or bearing a heavy load, whether it be physical or emotional in nature. In general, anyone or anything that is loaded down with too much weight or responsibility is likely to feel bogged down, exhausted, or worn out.