The Spanish word 'boricua', meaning 'Puerto Rican', comes from the Taíno word 'Borikén' (also spelled as 'Boriquén'), which meant 'land of the brave lord'. This was the original Taíno name for the island that is now known as Puerto Rico. The term evolved from being the name of the island to referring to its inhabitants, similar to how 'American' can refer to people from America.

Since 'boricua' comes directly from the indigenous Taíno language and is specific to Puerto Rican identity, there aren't other common Spanish words that share its etymology.

There aren't any common English words related to 'boricua' since it comes from the Taíno language, which was native to the Caribbean and had limited influence on English. However, English speakers might recognize this word from Puerto Rican cultural contexts, such as in the phrase 'Yo soy Boricua, pa'que tu lo sepas' ('I am Puerto Rican, just so you know'), which has become a popular expression of Puerto Rican pride.