'bioavailability-enhancing' is a modern English compound formed from 'bioavailability' + the present participle 'enhancing'. 'Bioavailability' itself combines the prefix 'bio-' (from Greek 'bios', meaning 'life') and 'availability' (from 'available'), while 'enhance' comes from Old French via Latin roots meaning to raise or increase.

'bioavailability' developed in scientific English in the 20th century from 'bio-' + 'availability' to refer specifically to the fraction of an administered dose that reaches systemic circulation. 'Enhance' comes from Old French enhauncer (from Vulgar Latin *inaltiare), and the compound 'bioavailability-enhancing' arose as a descriptive technical term in pharmaceutical and biomedical contexts.

Initially, components like 'bio-' and 'availability' had general meanings ('life' and 'being obtainable'); in scientific usage they combined to mean the proportion of a substance that is available to produce an effect. 'Enhancing' retained the sense of 'increasing' or 'improving', so the compound's meaning is a straightforward technical extension: 'increasing bioavailability'.