'barnumize' originates from English, specifically from the proper name 'Barnum' (referring to P. T. Barnum), combined with the verb-forming suffix '-ize,' where '-ize' meant 'to make or become.'

'barnumize' was coined in modern English by attaching '-ize' to the surname 'Barnum' to form a verb meaning 'make like Barnum' or 'apply Barnum-style publicity'; it entered colloquial and journalistic usage in the 20th century to describe sensational promotion.

Initially, it meant 'to make like Barnum' in the literal sense of adopting showmanship; over time it came to mean more generally 'to sensationalize or hype something for popular appeal,' a sense that remains common.