'plethora' originates from Greek, specifically the word 'plēthōra,' where 'plēthōr' meant 'fullness.'

'plēthōra' transformed into the Late Latin word 'plethora,' and eventually became the modern English word 'plethora.'

Initially, it meant 'fullness or excess of bodily fluid,' but over time it evolved into its current meaning of 'an overabundance of something.'