The Spanish word 'alcatraz' (meaning 'pelican') comes from Arabic 'al-qaṭrás', which literally meant 'the one who walks proudly'. This Arabic term was formed by combining the Arabic definite article 'al-' ('the') with 'qaṭrás' meaning 'to walk proudly'. The name likely referred to the distinctive waddling gait and proud bearing of pelicans, which became associated with these large seabirds in Spanish.

Many Spanish words beginning with 'al-' share this Arabic origin of the definite article, such as 'algodón' (cotton), 'almohada' (pillow), and 'alfombra' (carpet), though these aren't directly related to 'alcatraz' beyond sharing the Arabic article prefix.

While not etymologically related, English speakers might be familiar with 'Alcatraz', the famous former prison island in San Francisco Bay, which was named after the pelicans that inhabited the island. The English word 'pelican' itself comes from a different etymology, derived from Latin 'pelicanus' and Ancient Greek 'pelekan'.