'haploidy' originates from Greek, specifically the word 'haploos,' where 'haploos' meant 'single' or 'simple,' combined with the suffix '-oid' meaning 'form' and '-y' forming a noun.

'haploidy' was formed in modern scientific English from the Greek roots and suffixes, and eventually became the modern English word 'haploidy.'

Initially, it meant 'the state of being haploid,' and this meaning has remained consistent in modern biological usage.