'sporadically-attended' originates from the combination of 'sporadic' and 'attended'. 'Sporadic' comes from the Medieval Latin 'sporadicus', meaning 'scattered', and 'attended' is derived from the Latin 'attendere', meaning 'to stretch toward'.

'Sporadicus' transformed into the English word 'sporadic', and 'attendere' evolved into 'attend', eventually forming the compound adjective 'sporadically-attended'.

Initially, 'sporadic' meant 'scattered or isolated', and 'attend' meant 'to be present'. Together, they evolved to describe events that are attended irregularly.