'monoploid' originates from Greek and New Latin roots: the prefix 'mono-' from Greek 'monos' meaning 'single' and the combining form '-ploid' (via New Latin/Modern scientific usage) from Greek element 'ploios/ploidos' meaning 'fold' or 'form'.

'monoploid' was formed in modern scientific English (via New Latin coinage) from the Greek-based combining elements 'mono-' + '-ploid' and entered genetics terminology in the late 19th to early 20th century to describe chromosome set counts.

Initially formed from elements meaning 'single' + 'fold/form', it came to be used specifically in genetics to mean 'having a single set of chromosomes'.