'inequally-sepaled' originates from Modern English, composed of the adjective 'inequally' (from Latin roots via Old French/Middle English, where the prefix 'in-' meant 'not' and Latin 'aequus' meant 'equal') and 'sepaled' (from New/Modern Latin 'sepalum', meaning 'sepal' or 'a calyx leaf').

'inequally' developed from Middle English and Old French forms derived from Latin 'in-' + 'aequus' meaning 'not equal'; 'sepal' is a 19th-century botanical coinage from Modern Latin 'sepalum', and combining them produced the compound descriptive term 'inequally-sepaled' in botanical English.

Initially the components meant 'not equal' and 'sepal (a calyx leaf)'; over time the compound came to be used specifically to describe flowers whose sepals differ in size or shape ('sepals not equal').