The Spanish word 'esclava' (meaning 'female slave') has a fascinating and somewhat dark etymology that traces back to the Slavic peoples' self-designation. It begins with the Slavic word 'sloveninu', which was simply what Slavic people called themselves. This term was borrowed into Byzantine Greek as 'sklabenós' to refer to Slavic people. Due to the historical context of many Slavic people being enslaved during the early Middle Ages, the Byzantine Greek word evolved into 'sklábos' meaning 'slave'. This term was then borrowed into Medieval Latin as 'sclavus', maintaining the meaning of 'slave', and finally made its way into Spanish as 'esclava', specifically referring to a female slave. This etymology reflects the unfortunate historical connection between the ethnonym of Slavic peoples and the institution of slavery in medieval Europe.

Some related Spanish words include 'esclavo' (male slave), 'esclavitud' (slavery), and 'esclavizar' (to enslave). These all share the same historical root and form a family of words relating to the concept of slavery.

The English word 'slave' is directly related to 'esclava', coming from the same Medieval Latin 'sclavus'. This connection makes it easy for English speakers to remember the Spanish word, as both languages preserve this historical connection between the Slavic peoples and the medieval slave trade. The English word 'Slav' or 'Slavic', referring to the ethnic group and language family, also comes from the same ultimate source, though it follows a different path of development that maintained its original ethnic meaning rather than the meaning relating to servitude.