The Spanish word 'memorias' comes from the Latin word 'memoria', meaning 'memory'. This Latin word was formed by combining the root 'memor' (meaning 'mindful' or 'remembering') with the suffix '-ia' (used to form abstract nouns). In Spanish, 'memoria' kept the same meaning as its Latin ancestor, and 'memorias' is simply the plural form created by adding the Spanish plural suffix '-s'.

While 'memoria' in Spanish refers to memory in general, 'memorias' (in the plural) is often used specifically to mean 'memoirs' or 'reminiscences' - written accounts of one's memories and experiences.

Some related Spanish words include 'memorable' (memorable), 'memorizar' (to memorize), and 'memorando' (memorandum). All these words share the same Latin root 'memor-' and relate to memory and remembering.

English speakers will recognize many cognates from the same Latin root: 'memory', 'memorable', 'memorize', 'memorial', and 'memorandum'. The connection is easy to see both in spelling and meaning, as all these words relate to remembering or preserving memories. The English word 'memory' comes from the same Latin 'memoria' as Spanish 'memoria'.