'multiflowered' originates from the Latin prefix 'multi-' (from Latin 'multus') meaning 'many', combined with the English word 'flower' (ultimately from Latin 'flōs, flōris' meaning 'flower') and the adjectival suffix '-ed' used to form adjectives meaning 'having'.

'multiflowered' developed as a modern English compound from 'multi-' + 'flowered' (i.e. 'multi-flowered'), where 'flowered' was already used in English as an adjective meaning 'having flowers'.

Initially and historically it has meant 'having many flowers'; this core meaning has remained essentially unchanged.