'mononucleate' originates from New Latin, specifically the word 'mononucleatus', where 'mono-' meant 'single' and 'nucleus' (from Latin) meant 'kernel' or 'nut'.

'mononucleate' changed from the New Latin word 'mononucleatus' and entered scientific English with the same basic form, eventually becoming the modern English 'mononucleate'.

Initially, it meant 'having a single nucleus', and over time it has retained this technical biological meaning.