'prostatic-inhibitory' originates from Modern English, a compound of the adjective 'prostatic' and the adjective 'inhibitory'; 'prostatic' ultimately comes from Greek/Latin 'prostate-' (from Greek 'prostátēs') and 'inhibitory' comes from Latin 'inhibere' meaning 'to hold in' or 'restrain'.

'prostatic' developed from Greek 'prostátēs' → Latin 'prostata'/'prostat-'; the noun 'prostate' entered English via Medieval/Latin usage and the adjective form 'prostatic' was formed in later English. 'Inhibitory' derives from Latin 'inhibēre' → Medieval Latin 'inhibēre'/'inhibitorius' → Middle/Modern English 'inhibit' and adjectival 'inhibitory'.

Initially the elements meant 'relating to the prostate' and 'tending to hold back'; the compound now specifically denotes 'tending to inhibit the prostate' in a medical or pharmacological sense.