'anti-nausea' originates from the combining form 'anti-' (Greek), meaning 'against', and the noun 'nausea' (from Latin 'nausea' via Greek 'nausia'), meaning 'seasickness' or 'discomfort in the stomach'.

'anti-' is a Greek prefix meaning 'against' that entered English via Latin and French use; 'nausea' comes from Greek 'nausia' (sea-sickness) and Latin 'nausea', and the compound 'anti-nausea' is a modern English formation combining the prefix and noun to mean 'against nausea'.

Initially the elements referred specifically to 'against' and 'sea-sickness'; over time they combined in English to form a broader medical/colloquial term meaning 'preventing or relieving nausea' generally, not only sea-sickness.