'regularly-watched' originates from the combination of 'regularly' and 'watched', where 'regularly' means 'at regular intervals' and 'watched' is the past participle of 'watch'.

'regularly' and 'watched' combined in modern English to form the adjective 'regularly-watched'.

Initially, 'regularly' meant 'at regular intervals' and 'watched' meant 'observed'. Together, they evolved to describe something frequently observed.