'PCR-inhibitory' originates as a modern technical compound joining the acronym 'PCR' (from 'polymerase chain reaction') and the adjective 'inhibitory'; 'PCR' is an abbreviation coined in the 1980s for the laboratory technique 'polymerase chain reaction', and 'inhibitory' ultimately derives from Latin 'inhibēre' meaning 'to hold back' or 'restrain'.

'inhibitory' developed from Latin 'inhibēre' (to hold back) through Late Latin and Middle English forms into the modern English adjective 'inhibitory'; 'PCR' emerged as an English-language acronym after the invention and naming of the technique in the early 1980s, and the compound 'PCR-inhibitory' appeared in late 20th to early 21st-century scientific literature to describe factors affecting that technique.

Initially, elements of the root meant 'to hold back' or 'restrain'; over time 'inhibitory' took on specialized biological and chemical senses of 'reducing activity' or 'blocking a process', and in modern usage 'PCR-inhibitory' specifically denotes agents or conditions that impede PCR amplification.