Pendulate is an interesting word that means to swing or to oscillate back and forth. It can be used for describing a wide range of objects or actions that exhibit this type of motion. Some synonyms for pendulate might include sway, swing, rock, wobble, vibrate, or undulate. These words all describe a similar type of motion, but each has its own connotations and subtleties that make it unique. For instance, "sway" might suggest a gentle motion like that of a tree branch in the wind, while "vibrate" might suggest a more rapid and intense shaking or quivering. By using different synonyms for pendulate, you can add nuance and variety to your language.