'logarithm' originates from Ancient Greek, specifically the word 'logarithmos', where 'logos' meant 'ratio' or 'proportion' and 'arithmos' meant 'number'.

'logarithmos' was adopted into Neo-Latin as 'logarithmus' in the early 17th century (coined by John Napier) and eventually entered English as 'logarithm'.

Initially, it referred to the coined term combining 'ratio' and 'number' used to simplify calculations; over time it evolved into the modern mathematical meaning of 'the exponent to which a given base must be raised to yield a number'.