impel comes from Latin impellere ('to push, drive forward'), from in- ('into') + pellere ('to push, drive'). Morphologically, the prefixed shape matters: the initial element belongs to the recorded formation and helps explain the modern form's surface analysis. In present English, the verb sense is "to drive or urge forward; to compel to act", so the historical development ends in a clearly identifiable modern dictionary use. The same base also appears in related forms such as compel, propel, expel, and repel, and in derivatives such as impeller and impellent. Its semantic neighborhood includes drive, compel, propel, and urge, which helps locate the modern sense without adding a separate etymological claim. The named historical forms include Latin impellere, Latin pellere, and Proto-Indo-European *pelh₂-.