The Spanish word 'avena' comes directly from the Latin word 'avēna', which also meant 'oats'. This is a straightforward etymology where both the meaning and form have remained remarkably stable from Latin to modern Spanish, with only the loss of the long vowel marking (ē) as Latin evolved into Spanish.

The word 'avena' is relatively basic in Spanish and is commonly used to refer to oats or oatmeal. You might see it in terms like 'avena integral' (whole oats) or 'harina de avena' (oat flour). There aren't many simpler Spanish words derived from the same root, as this is already a fundamental term.

While English 'oats' comes from a different Germanic root, the scientific name for the oat genus is 'Avena', borrowed directly from Latin. You might see this in scientific contexts or in discussions of agriculture. The word 'avenue' is unrelated, despite its similar spelling.