The Spanish word 'lagaña' (also spelled 'legaña'), meaning 'eye discharge' or 'sleep' (the crusty discharge that forms in the eyes), comes from the Latin word 'alligamen' meaning 'binding' or 'fastening'. This evolved through the Latin plural form 'alligamena' meaning 'sticky things', which was then shortened to 'ligamna'. The connection between the original meaning of 'binding' and the modern Spanish meaning of 'eye discharge' comes from the sticky, binding nature of eye secretions.

While 'lagaña' itself is a common Spanish word, there aren't many simpler or more commonly used Spanish words that share its specific etymology. However, it's worth noting that the word exists in two forms in Spanish: 'lagaña' and 'legaña', which are used interchangeably.

While there aren't direct English cognates of 'lagaña', English words like 'ligament' and 'ligature' share a distant relationship as they also come from Latin words related to binding or tying. These words all share the Latin root 'ligare' meaning 'to bind', though they evolved to describe different types of binding or connecting elements.