The word 扔掉 is formed by combining two characters that each contribute a layer of action to create a single, vivid concept. The first character, 扔, means "to throw". The second, 掉, carries a core sense of something falling down, dropping off, or coming away. When fused, the action of throwing is semantically completed by the implied result of that throw: the object falling away or being cast off. Thus, the compound pictorially represents the complete act of discarding, not just the initial motion, but the conclusive outcome of getting rid of something.