'tendinous' originates from Medieval Latin, specifically the word 'tendinosus,' where 'tendo' meant 'tendon' and the suffix '-osus' meant 'full of' or 'having the quality of.'

'tendinosus' changed from Medieval Latin to the Late Middle English word 'tendinous,' and eventually became the modern English word 'tendinous.'

Initially, it meant 'full of tendons' or 'having the quality of a tendon,' but over time it evolved into its current meaning of 'relating to or resembling a tendon.'