The Spanish word 'peseta', which refers to the former currency unit of Spain, comes from Catalan 'peceta', meaning 'small piece'. The Catalan word was formed by combining 'peça' (meaning 'piece') with the diminutive suffix '-eta'. The evolution from 'peceta' to 'peseta' involved a simple sound change where 'c' became 's', which was common when words were borrowed from Catalan into Spanish.

In Spanish, while 'peseta' itself was a fundamental word as the name of Spain's currency before the euro, there are related words like 'pieza' (piece), which comes from the same etymological root as Catalan 'peça'. This connection makes sense since coins can be thought of as small pieces of currency.

While English doesn't have many direct cognates with 'peseta', we can find related words through the 'piece' connection. The English word 'piece' itself is distantly related, coming from similar roots meaning a portion or part. Another related English word is 'patch', which also carries the notion of a piece of something.