'tastelessly-adorned' originates from the combination of 'tastelessly' and 'adorned'. 'Tastelessly' comes from 'tasteless', which means lacking flavor or aesthetic taste, and 'adorned' is the past participle of 'adorn', meaning to decorate or add beauty.

'Tastelessly-adorned' evolved from the combination of 'tasteless' and 'adorn', which have been used in English since the 16th and 14th centuries, respectively.

Initially, 'tasteless' referred to lacking flavor, but it evolved to include lacking aesthetic taste. 'Adorn' has consistently meant to decorate or embellish.