'infrequently-watched' originates from English, specifically formed by combining 'infrequently' and 'watched', where 'in-' meant 'not' and Latin 'frequens' meant 'repeated/regular', and Old English 'wæccan' meant 'to be awake, to watch'.

'infrequently' developed from Latin 'frequens' (via Old French and Middle English 'frequent') with the negative prefix 'in-' added in Late Middle English; 'watched' comes from Old English 'wæccan' > Middle English 'wacchen' and eventually became the modern English past participle 'watched', and the compound phrase arose by combining the adverb + past participle structure in Modern English.

Initially the components meant 'not frequent' (infrequently) and 'to be awake/observe' (watch); over time the combined expression came to mean 'rarely viewed' in contexts referring to viewing or audience attention.