'ageratum' originates from Greek, specifically the word 'ageratos,' where 'a-' meant 'not' and 'geras' meant 'old age,' referring to the plant's long-lasting flowers.

'ageratos' transformed into the Latin word 'ageratum,' and eventually became the modern English word 'ageratum.'

Initially, it meant 'not growing old,' referring to the plant's long-lasting flowers, and this meaning has largely remained the same in modern usage.