Origin

The character 阻 combines the radical for "mound" or "hill" on the left, which suggests a barrier or obstruction, with the component 且 on the right that serves as a sound hint for pronunciation. The idea of a mound or raised earth naturally evokes something that blocks or prevents passage, which connects to the meaning of obstruction. Over time, the character came to express the broader sense of thwarting or impeding something, whether physical or abstract.