'one-size-fits-all' originates from the concept of clothing designed to fit a wide range of body sizes, where 'one-size' meant 'a single size' and 'fits-all' meant 'suitable for everyone'.

The phrase 'one-size-fits-all' evolved from the clothing industry, where garments were labeled as 'one size fits all' to indicate they could accommodate various body types.

Initially, it referred specifically to clothing, but over time it evolved to describe solutions or approaches applicable to a wide range of situations.