'congruous' originates from Latin, specifically the word 'congruere,' where 'con-' meant 'together' and 'gruere' meant 'to fall or agree.'

'congruere' transformed into the Late Latin word 'congruus,' and eventually became the modern English word 'congruous' through Middle English.

Initially, it meant 'to agree or fall together,' and this meaning has largely remained the same in modern usage.