The term 'RETRO COPIER' is a combination of two words, 'RETRO' and 'COPIER'. The word 'RETRO' refers to something that is old-fashioned or out-of-date, while the word 'COPIER' is a device used to make copies of documents. The crossword solution for this term is 'Mimeo', which is a type of copying machine that was popular in the 1950s and 1960s. Mimeo machines were used to make copies of documents quickly and easily, and they are still used today in some places.