'adverb-less' originates from the English word 'adverb' combined with the suffix '-less', where 'adverb' refers to a word that modifies a verb, adjective, or other adverb, and '-less' means 'without'.

'adverb' comes from the Latin word 'adverbium', and the suffix '-less' is of Old English origin, forming the modern English word 'adverb-less'.

Initially, it meant 'without adverbs', and this meaning has remained consistent in modern usage.