The Spanish word 'racha', meaning 'gust of wind' or 'streak' (as in a streak of luck), comes from the Arabic word 'rajja' (ráǧǧa), which meant 'agitation' or 'storm'. This is one of many Spanish words that entered the language during the centuries of Arabic influence on the Iberian Peninsula. The semantic connection is clear - both words relate to sudden, forceful movements or events, whether literally in terms of wind and storms, or metaphorically as in a streak of fortune.

While 'racha' itself is a relatively common Spanish word, there aren't many simpler or more common Spanish words that share its Arabic etymology. This is because it came directly from Arabic rather than evolving from Latin like many Spanish words.

There aren't any commonly used English words that are etymologically related to 'racha', as its Arabic origin follows a separate path from most English vocabulary. However, English speakers might find it helpful to remember that 'racha' sounds a bit like 'rush', which can also describe quick, forceful movement - though this is just a coincidental similarity rather than a true etymological connection.