The Spanish word 'arrayán', meaning 'myrtle', traces its roots to Arabic origins. It comes from the Andalusi Arabic word 'arrayḥán', which also meant 'myrtle'. This in turn developed from Classical Arabic 'arrayḥan', which literally meant 'the aromatic one' - a fitting description for the fragrant myrtle plant. The transition from Arabic to Spanish involved the loss of the guttural 'ḥ' sound, which is common when Arabic words were adopted into Spanish, resulting in the modern Spanish pronunciation.

While 'arrayán' itself is a relatively unique word in Spanish derived directly from Arabic, there aren't many commonly used Spanish words that share its specific etymology. This is because it came into Spanish as a specialized botanical term from Arabic, rather than being part of a larger word family.

While English 'myrtle' and Spanish 'arrayán' refer to the same plant, they actually have different etymological origins - 'myrtle' comes from ancient Greek via Latin, while 'arrayán' comes from Arabic. There aren't any common English words directly related to 'arrayán' since they developed from different language families.