'actinium-based' originates from the element 'actinium', which was named after the Greek word 'aktinos', meaning 'ray' or 'beam', due to its radioactive properties.

'Actinium' was discovered in 1899 by Friedrich Oskar Giesel and was named in 1902 by André-Louis Debierne. The term 'actinium-based' evolved as a descriptor for compounds or materials containing actinium.

Initially, 'actinium' referred solely to the element itself, but over time, 'actinium-based' has come to describe any material or compound containing actinium.